Electronic device and method for indicating non-scheduled layers in a fronthaul interface - Patent Application 20070122997

Abstract

In an embodiment, an electronic device of a radio unit (RU) may include at least one fronthaul transceiver, at least one radio frequency (RF) transceiver, and at least one processor coupled to the at least one fronthaul transceiver and the at least one RF transceiver. The at least one processor may be configured to receive a control plane (C-plane) message from a distributed unit (DU) via a fronthaul interface, the control plane (C-plane) message including information regarding a resource region and user equipment (UE) identification information corresponding to a value indicating non-scheduling of a layer. The at least one processor may be configured to calculate beamforming weights based on the C-plane message. The at least one processor may be configured to perform beamforming based on the beamforming weights.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to fronthaul interfaces, and more particularly to electronic devices and methods for indicating a non-scheduling layer in a fronthaul interface. [Background technology]

[0002] As transmission capacity increases in wireless communication systems, function splitting, which functionally separates base stations, is being applied. According to function splitting, a base station can be separated into a distributed unit (DU) and a radio unit (RU). A fronthaul interface is defined for communication between the DU and the RU. The preceding information may be provided as related art to aid in the understanding of the present disclosure. No assertion or determination is being made as to the applicability of any of the preceding as prior art pertaining to the present disclosure. Summary of the Invention [Means for solving the problem]

[0003] In an embodiment, an electronic device for a radio unit (RU) is provided. The electronic device may include at least one fronthaul transceiver, at least one radio frequency (RF) transceiver, and at least one processor coupled to the at least one fronthaul transceiver and the at least one RF transceiver. The at least one processor may be configured to receive a control plane (C-plane) message from a distributed unit (DU) via a fronthaul interface, the control plane (C-plane) message including information regarding a resource region and user equipment (UE) identification information corresponding to a value indicating non-scheduling of a layer. The at least one processor may be configured to calculate beamforming weights based on the C-plane message. The at least one processor may be configured to perform beamforming based on the beamforming weights.

[0004] In an embodiment, an electronic device for a distributed unit (DU) is provided. The electronic device may include at least one transceiver and at least one processor coupled to the at least one transceiver. The at least one processor may be configured to identify non-scheduling of a layer in a resource region. The at least one processor may be configured to generate a control plane (C-plane) message including information about the resource region and user equipment (UE) identification information corresponding to a value indicating the non-scheduling of the layer. The at least one processor may be configured to transmit the generated C-plane message to a radio unit (RU). The C-plane message may be associated with beamforming weights in the RU.

[0005] In an embodiment, a method performed by a radio unit (RU) is provided. The electronic device may include receiving, via a fronthaul interface, a control plane (C-plane) message from a distributed unit (DU) including information regarding a resource region and user equipment (UE) identification information corresponding to a value indicating non-scheduling of a layer. The method may include calculating beamforming weights based on the C-plane message. The method may include performing beamforming based on the beamforming weights.

[0006] In an embodiment, a method is provided that is performed by a distributed unit (DU). The electronic device may include an operation of identifying a non-scheduling layer in a resource region. The method may include an operation of generating a control plane (C-plane) message including information about the resource region and user equipment (UE) identification information corresponding to a value indicating the non-scheduling of the layer. The method may include an operation of transmitting the generated C-plane message to a radio unit (RU). The C-plane message may be associated with beamforming weights in the RU.

[0007] In an embodiment, a method performed by a radio unit (RU) is provided. The method may include an operation of receiving, from a distributed unit (DU), a control plane (C-plane) message including section information for user equipment (UE) scheduling information and section extension information for group configuration of multiple ports. The section information may include information regarding a resource region of a section description and UE identification information. The section extension information may include information regarding a beam group type, information regarding the number of one or more ports indicated by the section extension information, and port-specific UE identification information. The method may include an operation of identifying, based on the UE identification information of a designated port set to 0x7FFF in the C-plane message, that the resource region is not allocated to the designated port.

[0008] In an embodiment, a method performed by a distributed unit (DU) is provided. The method may include an operation of setting UE identification information of a designated port that is not to be scheduled to 0x7FFF. The method may include an operation of transmitting a control plane (C-plane) message to a radio unit (RU), the control plane (C-plane) message including section information for user equipment (UE) scheduling information and section extension information for group configuration of multiple ports. The section information may include information regarding a resource region of a section description and UE identification information. The section extension information may include information regarding a beam group type, information regarding the number of one or more ports indicated by the section extension information, and port-specific UE identification information. The UE identification information of the designated port in the C-plane message may indicate that the resource region is not allocated to the designated port.

[0009] In an embodiment, an electronic device for a radio unit (RU) is provided. The electronic device may include a memory including instructions, at least one transceiver configured to transmit or receive signals over a fronthaul interface, and at least one processor. When executed by the at least one processor, the instructions may cause the RU to receive, from a distributed unit (DU), a control plane (C-plane) message including section information for user equipment (UE) scheduling information and section extension information for group configuration of multiple ports. The section information may include information regarding a resource region of a section description and UE identification information. The section extension information may include information regarding a beam group type, information regarding the number of one or more ports indicated by the section extension information, and port-specific UE identification information. When executed by the at least one processor, the instructions may cause the RU to identify that the resource region is not allocated to a designated port based on the UE identification information of the designated port set to 0x7FFF in the C-plane message.

[0010] In an embodiment, an electronic device for a distributed unit (DU) is provided. The electronic device may include a memory including instructions, at least one transceiver configured to transmit or receive signals over a fronthaul interface, and at least one processor. The instructions, when executed by the at least one processor, may cause the DU to set UE identification information of a designated port to which the DU is not scheduled to 0x7FFF. The instructions, when executed by the at least one processor, may cause the DU to transmit, to a radio unit (RU), a control plane (C-plane) message including section information for user equipment (UE) scheduling information and section extension information for group configuration of multiple ports. The section information includes information about a resource region of a section description and UE identification information, and the section extension information may include information about a beam group type, information about the number of one or more ports indicated by the section extension information, and port-specific UE identification information. The UE identification information of the designated port in the C-plane message may indicate that the resource region is not allocated to the designated port.

[0011] In an embodiment, a non-transitory computer-readable medium is provided. The non-transitory computer-readable medium may include a memory storing a program including instructions. When executed by a processor of a radio unit (RU), the instructions may cause the RU to receive, from a distributed unit (DU), a control plane (C-plane) message including section information for user equipment (UE) scheduling information and section extension information for group configuration of multiple ports, and to identify, based on UE identification information of a designated port set to 0x7FFF in the C-plane message, that a resource region in the section description is not allocated to the designated port. The section information may include information about the resource region and UE identification information. The section extension information may include information about a beam group type, information about the number of one or more ports indicated by the section extension information, and port-specific UE identification information.

[0012] In an embodiment, a non-transitory computer-readable medium is provided. The non-transitory computer-readable medium may include a memory storing a program including instructions. When executed by a processor of a distributed unit (DU), the instructions may cause the DU to set UE identification information of a designated port not to be scheduled to 0x7FFF and transmit a control plane (C-plane) message to a radio unit (RU), the control plane (C-plane) message including section information for user equipment (UE) scheduling information and section extension information for group configuration of multiple ports. The section information may include information regarding a resource region of a section description and UE identification information. The section extension information may include information regarding a beam group type, information regarding the number of one or more ports indicated by the section extension information, and port-specific UE identification information. The UE identification information of the designated port in the C-plane message may indicate that the resource region is not allocated to the designated port. [Brief explanation of the drawings]

[0013] [Figure 1] 1 illustrates a wireless communication system according to an embodiment. [Figure 2A] 1 illustrates a fronthaul interface according to an embodiment. [Figure 2B] 1 illustrates a fronthaul interface of an O (open)-RAN (radio access network) according to an embodiment. [Figure 3A] 1 illustrates components of a distributed unit (DU) according to an embodiment. [Figure 3B] 1 illustrates components of a radio unit (RU) according to an embodiment. [Figure 4] 1 illustrates an example of function split between a DU and a RU according to an embodiment. [Figure 5A] 1 illustrates an example of a downlink (DL) message according to an embodiment. [Figure 5B] 1 illustrates an example of an uplink (UL) message according to an embodiment. [Figure 6] 1 illustrates an example of resource allocation by layer according to one embodiment. [Figure 7A] 1 illustrates an example of beamforming utilizing non-scheduling layer indications, according to one embodiment. [Figure 7B] 1 illustrates an example of beamforming utilizing non-scheduling layer indications, according to one embodiment. [Figure 8] 10 illustrates an example of beamforming weights for each resource region according to an embodiment. [Figure 9] 1 illustrates the functional configuration of a DU and a RU for beamforming using instructions from a non-scheduling layer according to one embodiment. [Figure 10] 10 illustrates a DU operation flow for non-scheduling layer indication according to one embodiment. [Figure 11] 10 illustrates an operational flow of an RU for non-scheduling layer indication according to one embodiment. [Figure 12A] 10 illustrates an example of a C-plane message for non-scheduling layer indication according to one embodiment. [Figure 12B] 10 illustrates an example of a C-plane message for non-scheduling layer indication according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] The terms used in this disclosure are merely used to describe specific embodiments and are not intended to limit the scope of other embodiments. A singular expression can include a plural expression unless otherwise specified in the context. Terms used herein, including technical or scientific terms, can have the same meaning as commonly understood by a person of ordinary skill in the art described in this disclosure. Among the terms used in this disclosure, terms defined in common dictionaries may be interpreted as having the same or similar meaning as in the context of the relevant art, and unless clearly defined in this disclosure, they should not be interpreted as having an ideal or overly formal meaning. In some cases, even terms defined in this disclosure cannot be interpreted to exclude embodiments of the present disclosure.

[0015] In the various embodiments of the present disclosure described below, a hardware approach is described as an example, however, various embodiments of the present disclosure include techniques that use both hardware and software, and therefore various embodiments of the present disclosure do not exclude a software-based approach.

[0016] The following description uses terms that refer to signals (e.g., packet, message, signal, information, signaling), resources (e.g., section, symbol, slot, subframe, radio frame, subcarrier, resource element (RE), resource block (RB), bandwidth part (BWP), occasion), operation states (e.g., step, operation, procedure), data (e.g., packet, message, user stream, information, bit, symbol, codeword), channels, and network entities (e.g., distributed unit (DU), radio unit (RU), central unit (CU), control plane (CU-CP), user plane (CU-UP), open radio access network (O-DU), open radio access network (O-RU), and so on). Terms such as "RU", "O-RAN CU", "O-CU-UP", "O-RAN CU-CP", "O-CU-CP", and terms referring to device components are exemplified for the convenience of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms having equivalent technical meanings may be used. Furthermore, terms such as "part", "container", "object", and "body" used below may mean at least one shape structure or a unit that processes a function.

[0017] Furthermore, in this disclosure, expressions such as "more than" or "less than" may be used to determine whether a particular condition is satisfied or fulfilled, but this is merely an explanation for illustrating an example and does not exclude descriptions such as "more than" or "less than." A condition described as "more than" can be replaced with "more than," a condition described as "less than," and a condition described as "more than and less than" can be replaced with "more than and less than." Furthermore, hereinafter, "A" to "B" refer to at least one element from A to B (including B).

[0018] Although the present disclosure describes various embodiments using terminology used in some communication standards (e.g., 3GPP (3rd Generation Partnership Project), xRAN (extensible radio access network), and O-RAN (open-radio access network), this is for illustrative purposes only. Various embodiments of the present disclosure can be easily modified and applied to other communication systems.

[0019] FIG. 1 shows a wireless communication system according to an embodiment.

[0020] 1, which illustrates a base station 110 and a terminal 120 as some of the nodes utilizing wireless channels in a wireless communication system. Although FIG. 1 shows only one base station, the wireless communication system may further include other base stations that are the same as or similar to base station 110.

[0021] The base station 110 is a network infrastructure that provides wireless connectivity to the terminal 120. The base station 110 has coverage that is defined based on the distance over which a signal can be transmitted. In addition to a base station, the base station 110 may also be referred to as an "access point (AP)," "eNodeB (eNB)," "5th generation node," "gNodeB (gNB)," "wireless point," "transmission / reception point (TRP)," or other terms having an equivalent technical meaning.

[0022] The terminal 120 is a device used by a user and communicates with the base station 110 via a wireless channel. A link from the base station 110 to the terminal 120 is called a downlink (DL), and a link from the terminal 120 to the base station 110 is called an uplink (UL). Although not shown in FIG. 1 , the terminal 120 and other terminals can communicate with each other via wireless channels. In this case, a device-to-device link (D2D) between the terminal 120 and other terminals is called a sidelink, and the term sidelink may be used interchangeably with a PC5 interface. In some other embodiments, the terminal 120 can be operated without user involvement. According to one embodiment, the terminal 120 is a device for performing machine type communication (MTC) and may not be carried by a user. Furthermore, according to one embodiment, the terminal 120 may be a narrowband (NB)-Internet of Things (IoT) device.

[0023] Terminal 120 may also be referred to as a terminal, "user equipment (UE)," "customer premises equipment (CPE)," "mobile station," "subscriber station," "remote terminal," "wireless terminal," electronic device, or "user device," or other terms having equivalent technical meanings.

[0024] The base station 110 may perform beamforming with the terminal 120. The base station 110 and the terminal 120 may transmit and receive radio signals in a relatively low frequency band (e.g., FR1 (frequency range 1) of NR). The base station 110 and the terminal 120 may also transmit and receive radio signals in a relatively high frequency band (e.g., FR2 (or FR2-1, FR2-2, FR2-3), or FR3 of NR) or a millimeter wave (mmWave) band (e.g., 28 GHz, 30 GHz, 38 GHz, or 60 GHz). To improve channel gain, the base station 110 and the terminal 120 may perform beamforming. Here, beamforming may include transmit beamforming and receive beamforming. The base station 110 and the terminal 120 may impart directionality to a transmit signal or a receive signal. To this end, the base station 110 and the terminal 120 can select a serving beam through a beam search or beam management procedure. After the serving beam is selected, communication can be performed via resources that have a QCL relationship with the resources that transmit the serving beam.

[0025] A first antenna port and a second antenna port can be evaluated as having a QCL relationship if large-scale characteristics of the channel that carried symbols on the first antenna port can be inferred from the channel that carried symbols on the second antenna port. For example, the large-scale characteristics can include at least one of delay spread, Doppler spread, Doppler shift, average gain, average delay, and spatial receiver parameters.

[0026] 1 shows both base station 110 and terminal 120 performing beamforming, embodiments of the present disclosure are not necessarily limited thereto. In some embodiments, the terminal may or may not perform beamforming. Also, the base station may or may not perform beamforming. That is, only one of the base station and the terminal may perform beamforming, or neither the base station nor the terminal may perform beamforming.

[0027] In this disclosure, a beam refers to a spatial flow of a signal in a wireless channel and is formed by one or more antennas (or antenna elements), and such a forming process may be referred to as beamforming. Beamforming may include at least one of analog beamforming or digital beamforming (e.g., precoding). Reference signals transmitted based on beamforming may include, for example, a demodulation-reference signal (DM-RS), a channel state information-reference signal (CSI-RS), a synchronization signal / physical broadcast channel (SS / PBCH), and a sounding reference signal (SRS). Furthermore, an IE such as a CSI-RS resource or an SRS resource may be used as the configuration of each reference signal, and such a configuration may include information associated with the beam. The beam-related information may refer to whether the configuration (e.g., a CSI-RS resource) uses the same spatial domain filter as other configurations (e.g., other CSI-RS resources in the same CSI-RS resource set) or whether a different spatial domain filter is used, or which reference signal it is quasi-co-located with, and if so, what type it is (e.g., QCL type A, B, C, D).

[0028] In the past, in a communication system in which the cell radius of a base station is relatively large, each base station was installed to include the functions of a digital processing unit (or DU (distributed unit)) and an RF (radio frequency) processing unit (RF processing unit, or RU (radio unit)).th In communication systems of the 2020 (next generation) and / or later generations (e.g., 5G), higher frequency bands are used, and as the cell coverage of base stations becomes smaller, the number of base stations required to cover a specific area increases. The installation costs borne by operators for installing base stations have also increased. To minimize the installation costs of base stations, a structure has been proposed in which the DU and RU of a base station are separated, one or more RUs are connected to one DU via a wired network, and one or more RUs are geographically distributed to cover a specific area. Below, examples of base station deployment structures and expansions according to various embodiments of the present disclosure will be described with reference to FIGS. 2A and 2B.

[0029] FIG. 2A illustrates a fronthaul interface according to an embodiment. Fronthaul, unlike backhaul between a base station and a core network, refers to an entity between a wireless LAN and a base station. While FIG. 2A illustrates an example of a fronthaul structure between a DU 210 and one RU 220, this is merely for convenience of explanation, and the present disclosure is not limited thereto. In other words, embodiments of the present disclosure may also be applied to a fronthaul structure between one DU and multiple RUs. For example, embodiments of the present disclosure may be applied to a fronthaul structure between one DU and two RUs. Furthermore, embodiments of the present disclosure may also be applied to a fronthaul structure between one DU and three RUs.

[0030] 2A, the base station 110 may include a DU 210 and an RU 220. A fronthaul 215 between the DU 210 and the RU 220 may be implemented by F x The fronthaul 215 can be operated via an interface, such as an enhanced common public radio interface (eCPRI) or a radio over ethernet (ROE).

[0031] As communication technology develops, mobile data traffic increases, which significantly increases the bandwidth requirements for the fronthaul between digital units and wireless units. In deployments such as C-RAN (centralized / cloud radio access network), the DU performs functions for packet data convergence protocol (PDCP), radio link control (RLC), media access control (MAC), and physical layer (PHY), while the RU can be implemented to perform functions for the PHY layer in addition to radio frequency (RF) functions.

[0032] The DU 210 may be responsible for higher layer functions of a wireless network. For example, the DU 210 may perform functions of the MAC layer and part of the PHY layer. Here, the part of the PHY layer refers to functions of the PHY layer performed at a higher stage, and may include, for example, channel coding (or channel decoding), scrambling (or descrambling), modulation (or demodulation), and layer mapping (or layer demapping). According to one embodiment, if the DU 210 complies with the O-RAN standard, it may be referred to as an O-DU (O-RAN DU). If necessary, the DU 210 may be expressed as a first network entity for a base station (e.g., a gNB) in the embodiments of the present disclosure.

[0033] The RU 220 may be responsible for functions of lower layers of a radio network. For example, the RU 220 may perform part of the PHY layer and RF functions. Here, the part of the PHY layer refers to PHY layer functions that are performed at a stage relatively lower than that of the DU 210, and may include, for example, iFFT (or FFT) transformation, CP insertion (CP removal), and digital beamforming. A specific example of such functional separation is shown in detail in FIG. 4. The RU 220 may be referred to as an "access unit (AU)," "access point (AP)," "transmission / reception point (TRP)," "remote radio head (RRH)," "radio unit (RU)," or other terms having equivalent technical meanings. According to an embodiment, if the RU 220 complies with the O-RAN standard, it may be referred to as an O-RU (O-RAN RU). The RU 220 may be substituted for a second network entity for a base station (e.g., a gNB) in the embodiments of the present disclosure, as needed.

[0034] Although FIG. 2A illustrates the base station 110 including the DU 210 and the RU 220, embodiments of the present disclosure are not limited thereto. A base station according to an embodiment may be implemented in a distributed deployment with a centralized unit (CU) configured to perform functions of upper layers (e.g., packet data convergence protocol (PDCP) and radio resource control (RRC)) of an access network and a distributed unit (DU) configured to perform functions of lower layers. In this case, the distributed unit (DU) may include the digital unit (DU) and radio unit (RU) of FIG. 1. Between a core (e.g., 5G core (5GC) or next generation core (NGC)) network and a radio network (RAN), the base station may be implemented in a structure in which the CU, DU, and RU are arranged in this order. The interface between the CU and the distributed unit (DU) may be referred to as an F1 interface.

[0035] A centralized unit (CU) is connected to one or more DUs and can perform functions of higher layers than the DUs. For example, the CU can perform functions of the radio resource control (RRC) and packet data convergence protocol (PDCP) layers, while the DU and RU can perform functions of lower layers. The DU can perform radio link control (RLC), media access control (MAC), and some functions of the physical layer (PHY) (high PHY), while the RU can perform the remaining functions of the PHY layer (low PHY). Furthermore, in one example, a digital unit (DU) may be included in a distributed unit (DU) depending on the implementation of a distributed deployment of a base station. Hereinafter, unless otherwise defined, the operation of a digital unit (DU) and an RU will be described. However, various embodiments of the present disclosure can be applied to both a deployment of a base station including a CU and a deployment in which a DU is directly connected to a core network (i.e., a deployment in which the CU and DU are integrated and implemented in a single entity, such as a base station (e.g., an NG-RAN node)).

[0036] 2B illustrates a fronthaul interface of an open (O)-RAN (radio access network) according to an embodiment. A base station 110 in a distributed deployment is exemplified by an eNB or a gNB.

[0037] 2B , base station 110 may include O-DU 251 and O-RUs 253-1, ..., 253-n. Hereinafter, for convenience of explanation, the operations and functions of O-RU 253-1 may be understood as descriptions of each of the other O-RUs (e.g., O-RU 253-n).

[0038] The O-DU 251 is a logical node including functions of a base station (e.g., eNB, gNB) according to FIG. 4 (described later) except for functions exclusively assigned to the O-RU 253-1. The O-DU 251 can control the operation of the O-RUs 253-1, ..., 253-n. The O-DU 251 is sometimes referred to as a lower layer split (LLS) central unit (CU). The O-RU 253-1 is a logical node including a subset of the functions of a base station (e.g., eNB, gNB) according to FIG. 4 (described later). Real-time aspects of control plane (C-plane) and user plane (U-plane) communications with the O-RU 253-1 can be controlled by the O-DU 251.

[0039] The O-DU251 can communicate with the O-RU253-1 via the LLS interface. The LLS interface corresponds to the fronthaul interface. The LLS interface refers to a logical interface between the O-DU251 and the O-RU253-1 that uses lower layer functional split (i.e., intra-PHY-based functional split). The LLS-C between the O-DU251 and the O-RU253-1 provides the C-plane via the LLS interface. The LLS-U between the O-DU251 and the O-RU253-1 provides the U-plane via the LLS interface.

[0040] In FIG. 2B , to explain the O-RAN, the entities of the base station 110 are referred to as the O-DU and the O-RU. However, such names are not to be construed as limiting the embodiments of the present disclosure. In the embodiments described with reference to FIGS. 3A to 12B , it goes without saying that the operations of the DU 210 can be performed by the O-DU 251. The description of the DU 210 can also be applied to the O-DU 251. Similarly, in the embodiments described with reference to FIGS. 3A to 12B , it goes without saying that the operations of the RU 220 can also be performed by the O-RU 253-1. The description of the RU 220 can also be applied to the O-RU 253-1.

[0041] Figure 3A shows components of a distributed unit (DU) according to an embodiment. The configuration shown in Figure 3A can be understood as the configuration of the DU 210 in Figure 2A (or the O-DU 250 in Figure 2B) as part of a base station. As used below, the terms "... unit" and "... device" refer to a unit that processes at least one function or operation, and can be implemented in hardware, software, or a combination of hardware and software.

[0042] Referring to FIG. 3A, the DU 210 includes a transceiver 310, a memory 320, and a processor 330.

[0043] The transceiver 310 may perform functions for transmitting and receiving signals in a wired communication environment. The transceiver 310 may include a wired interface for controlling a direct connection between devices via a transmission medium (e.g., copper wire, optical fiber). For example, the transceiver 310 may transmit electrical signals to other devices via copper wires or perform conversion between electrical and optical signals. The DU 210 may communicate with a radio unit (RU) via the transceiver 310. The DU 210 may be connected to a core network or a CU in a distributed configuration via the transceiver 310.

[0044] The transceiver 310 may also perform functions for transmitting and receiving signals in a wireless communication environment. For example, the transceiver 310 may perform functions for converting between baseband signals and bit streams in accordance with the system's physical layer specifications. For example, when transmitting data, the transceiver 310 encodes and modulates the transmit bit stream to generate complex symbols. When receiving data, the transceiver 310 demodulates and decodes the baseband signal to recover the received bit stream. Furthermore, the transceiver 310 may include multiple transceiver paths. Furthermore, according to one embodiment, the transceiver 310 may be connected to a core network or to other nodes (e.g., an integrated access backhaul (IAB)).

[0045] The transceiver 310 may transmit and receive signals. For example, the transceiver 310 may transmit management plane (M-plane) messages. For example, the transceiver 310 may transmit synchronization plane (S-plane) messages. For example, the transceiver 310 may transmit control plane (C-plane) messages. For example, the transceiver 310 may transmit user plane (U-plane) messages. For example, the transceiver 310 may receive user plane messages. Although only the transceiver 310 is shown in FIG. 3A, according to other embodiments, the DU 210 may include two or more transceivers.

[0046] The transceiver 310 transmits and receives signals as described above. Therefore, all or part of the transceiver 310 may be referred to as a "communication unit," a "transmitter," a "receiver," or a "transmitter / receiver unit." In the following description, transmission and reception via a wireless channel are used to mean that the transceiver 310 performs the processing described above.

[0047] 3A, the transceiver 310 may further include a backhaul transceiver for connecting to a core network or another base station. The backhaul transceiver provides an interface for communicating with other nodes in the network. That is, the backhaul transceiver converts bit strings transmitted from the base station to other nodes, such as other access nodes, other base stations, upper nodes, and the core network, into physical signals, and converts physical signals received from other nodes into bit strings.

[0048] The memory 320 stores data such as basic programs, application programs, and setting information for the operation of the DU 210. The memory 320 may be called a storage unit. The memory 320 may be configured as a volatile memory, a nonvolatile memory, or a combination of a volatile memory and a nonvolatile memory. The memory 320 provides the stored data according to a request from the processor 330.

[0049] The processor 330 controls the overall operation of the DU 210. The processor 380 may be referred to as a control unit. For example, the processor 330 transmits and receives signals via the transceiver 310 (or via a backhaul communication unit). Furthermore, the processor 330 writes and reads data to the memory 320. The processor 330 can also perform protocol stack functions required by communication standards. Although only the processor 330 is shown in FIG. 3A, according to other embodiments, the DU 210 may include two or more processors.

[0050] The configuration of the DU 210 shown in Fig. 3A is an example and is not limited to an example of a DU that executes an embodiment of the present disclosure from the configuration shown in Fig. 3A. In some embodiments, some components may be added, deleted, and changed. Figure 3B shows components of an RU (radio unit) according to an embodiment. The configuration shown in Figure 3B can be understood as the configuration of the RU 220 in Figure 2B or the O-RU 253-1 in Figure 2B as part of a base station. As used below, the terms "unit," "device," etc. refer to a unit that processes at least one function or operation, and can be implemented in hardware, software, or a combination of hardware and software.

[0051] Referring to FIG. 3B, the RU 220 includes an RF transceiver 360, a fronthaul transceiver 365, a memory 370, and a processor 380. The RF transceiver 360 performs functions for transmitting and receiving signals over a wireless channel. For example, the RF transceiver 360 upconverts a baseband signal to an RF band signal and then transmits the signal via an antenna. The RF transceiver 360 downconverts an RF band signal received via the antenna back to a baseband signal. For example, the RF transceiver 360 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc.

[0052] The RF transceiver 360 may include multiple transceiver paths. Furthermore, the RF transceiver 360 may include an antenna section. The RF transceiver 360 may include at least one antenna array consisting of multiple antenna elements. In terms of hardware, the RF transceiver 360 may be configured with digital and analog circuits (e.g., a radio frequency integrated circuit (RFIC)). Here, the digital and analog circuits may be implemented in a single package. Furthermore, the RF transceiver 360 may include multiple RF chains. The RF transceiver 360 may perform beamforming. The RF transceiver 360 may apply beamforming weights to signals to impart directionality to signals desired to be transmitted or received according to settings by the processor 380. According to one embodiment, the RF transceiver 360 may include a radio frequency (RF) block (or RF section).

[0053] According to one embodiment, the RF transceiver 360 can transmit and receive signals over a radio access network. For example, the RF transceiver 360 can transmit downlink signals. The downlink signals can include synchronization signals (SS), reference signals (RS) (e.g., cell-specific reference signals (CRS), demodulation-RS (DM)), system information (e.g., MIB, SIB, remaining system information (RMSI), other system information (OSI)), configuration messages, control information, downlink data, etc. Additionally, for example, the RF transceiver 360 can receive uplink signals. The uplink signals may include random access related signals (e.g., random access preamble (RAP) (or Msg1 (message 1)), Msg3 (message 3)), reference signals (e.g., SRS (sounding reference signal), DM-RS), or power headroom reports (PHR), etc. Although only RF transceiver 360 is shown in FIG. 3B, according to other embodiments, RU 220 may include two or more RF transceivers.

[0054] According to an embodiment, the RF transceiver 460 can transmit a RIM-RS. The RF transceiver 460 can transmit a first type of RIM-RS (e.g., 3GPP® RIM-RS Type 1) to indicate detection of a distant interferer. The RF transceiver 460 can transmit a second type of RIM-RS (e.g., 3GPP® RIM-RS Type 2) to indicate the presence or absence of a distant interferer.

[0055] The fronthaul transceiver 365 may transmit and receive signals. According to one embodiment, the fronthaul transceiver 365 may transmit and receive signals over a fronthaul interface. For example, the fronthaul transceiver 365 may receive management plane (M-plane) messages. For example, the fronthaul transceiver 365 may receive synchronization plane (S-plane) messages. For example, the fronthaul transceiver 365 may receive control plane (C-plane) messages. For example, the fronthaul transceiver 365 may transmit user plane (U-plane) messages. For example, the fronthaul transceiver 365 may receive user plane messages. Although only the fronthaul transceiver 365 is shown in FIG. 3B, according to other embodiments, the RU 220 may include two or more fronthaul transceivers.

[0056] The RF transceiver 360 and the fronthaul transceiver 365 transmit and receive signals as described above. Therefore, all or part of the RF transceiver 360 and the fronthaul transceiver 365 may be referred to as a "communication unit," a "transmitter," a "receiver," or a "transmitter / receiver unit." In the following description, transmission and reception performed via a wireless channel are used to mean that the RF transceiver 360 performs the processing described above. In the following description, transmission and reception performed via a wireless channel are used to mean that the RF transceiver 360 performs the processing described above.

[0057] The memory 370 stores data such as basic programs, application programs, and configuration information for the operation of the RU 220. The memory 370 may be referred to as a storage unit. The memory 370 may be configured as a volatile memory, a nonvolatile memory, or a combination of a volatile memory and a nonvolatile memory. The memory 370 provides the stored data in accordance with a request from the processor 380. According to one embodiment, the memory 370 may include memory for conditions, instructions, or setting values ​​related to the SRS transmission method.

[0058] The processor 380 controls the overall operation of the RU 220. The processor 380 may be referred to as a controller. For example, the processor 380 transmits and receives signals via the RF transceiver 360 or the fronthaul transceiver 365. Furthermore, the processor 380 writes and reads data to and from the memory 370. The processor 380 may also execute protocol stack functions required for communication standards. While only the processor 380 is shown in FIG. 3B , in other embodiments, the RU 220 may include two or more processors. The processor 380 may be an instruction set or code stored in the memory 370, instructions / code that are at least temporarily resident in the processor 380, a memory space containing the instructions / code, or part of a circuit constituting the processor 380. The processor 380 may also include various modules for performing communication. The processor 380 may control the RU 220 to perform operations according to the following embodiments.

[0059] The configuration of RU 220 shown in Figure 3B is an example and is not limited to examples of RUs that implement embodiments of the present disclosure from the configuration shown in Figure 3B. In some embodiments, some components may be added, deleted, or changed.

[0060] FIG. 4 illustrates an example of function split between a DU and a RU according to an embodiment. As wireless communication technology develops (e.g., with the introduction of 5G (5th generation) communication systems (or NR (new radio) communication systems)), the number of available frequency bands has increased. As the cell radius of base stations has become increasingly smaller, the number of RUs required for installation has also increased. Furthermore, in 5G communication systems, the amount of data transmitted has increased significantly by more than ten times, significantly increasing the transmission capacity of wired networks transmitted over the fronthaul. These factors can significantly increase the installation cost of wired networks in 5G communication systems. Therefore, in order to reduce the transmission capacity of the wired network and reduce the installation cost of the wired network, a "function split" can be used to transfer some of the functions of the DU's modem to the RU to reduce the transmission capacity of the fronthaul.

[0061] To reduce the burden on the DU, the role of the RU, which is currently only responsible for RF functions, can be expanded to include some physical layer functions. The more higher-layer functions the RU performs, the higher the RU's throughput, the greater the fronthaul transmission bandwidth, and the lower the latency constraints due to response processing. On the other hand, the more higher-layer functions the RU performs, the less virtualization gain there is, and the larger, weight, and cost of the RU. It is necessary to achieve optimal functional separation by considering the trade-off between the advantages and disadvantages mentioned above.

[0062] Referring to Figure 4, functional separation in the physical layer below the MAC layer is shown. For the downlink (DL) transmitting signals to a terminal via a wireless network, a base station may sequentially perform channel coding / scrambling, modulation, layer mapping, antenna mapping, RE mapping, digital beamforming (e.g., precoding), iFFT transformation / CP insertion, and RF conversion. For the uplink (UL) receiving signals from a terminal via a wireless network, a base station may sequentially perform RF transformation, FFT transformation / CP removal, digital beamforming (pre-combining), RE demapping, channel estimation, layer demapping, demodulation, and decoding / descrambling. The separation of uplink and downlink functions can be defined in various ways depending on the needs of vendors due to the aforementioned trade-offs, specification discussions, etc.

[0063] In the first functional separation 405, the RU performs RF functions, and the DU performs PHY functions. The first functional separation, in which the PHY functions are not actually implemented within the RU, may be referred to as Option 8, for example. In the second functional separation 410, the RU performs PHY functions such as iFFT transformation / CP insertion on the DL and FFT transformation / CP removal on the UL, and the DU performs the remaining PHY functions. In an example, the second functional separation 410 may be referred to as Option 7-1. In the third functional separation 420a, the RU performs PHY functions such as iFFT transformation / CP insertion on the DL and FFT transformation / CP removal and digital beamforming on the UL, and the DU performs the remaining PHY functions. In an example, the third functional separation 420a may be referred to as Option 7-2xCategory A. In the fourth functional separation 420b, the RU performs up to digital beamforming on both the DL and UL, and the DU performs higher-level PHY functions after digital beamforming. In one example, the fourth function separation 420b may be referred to as Option 7-2xCategory B. In the fifth function separation 425, the RU performs up to RE mapping (or RE demapping) on ​​both DL and UL, and the DU performs higher-level PHY functions after RE mapping (or RE demapping). In one example, the fifth function separation 425 may be referred to as Option 7-2. In the sixth function separation 430, the RU performs up to modulation (or demodulation) on both DL and UL, and the DU performs higher-level PHY functions after modulation (or demodulation). In one example, the sixth function separation 430 may be referred to as Option 7-3. In the seventh function separation 440, the RU performs up to encoding / scrambling (or decoding / descrambling) on ​​both DL and UL, and the DU performs higher-level PHY functions after modulation (or demodulation). In one example, the seventh function separation 440 may be referred to as Option 6.

[0064] According to one embodiment, when large-capacity signal processing such as that of an FR1 MMU is expected, functional separation at a relatively high layer (e.g., the fourth functional separation 420b) may be required to reduce the fronthaul capacity. Furthermore, functional separation at too high a layer (e.g., the sixth functional separation 430) may complicate the control interface and include many PHY processing blocks in the RU, which may burden the RU implementation. Therefore, appropriate functional separation may be required depending on the arrangement and implementation method of the DU and RU.

[0065] According to one embodiment, if the RU is unable to process precoding of data received from a DU (i.e., if the RU has limited precoding capability), the third function separation 420a or a lower function separation (e.g., the second function separation 410) can be applied. Conversely, if the RU is able to process precoding of data received from a DU, the fourth function separation 420b or a higher function separation (e.g., the sixth function separation 430) can be applied.

[0066] Hereinafter, unless otherwise limited, embodiments of the present disclosure will be described based on the third functional separation 420a (sometimes referred to as category A (CAT-A)) or the fourth functional separation 420b (sometimes referred to as category B (CAT-B)) for performing beamforming processing in the RU. The O-RAN standard distinguishes between types of O-RUs depending on whether the precoding function is located in the O-DU interface or the O-RU interface. An O-RU that does not perform precoding (i.e., has low complexity) may be referred to as a CAT-A O-RU. An O-RU that performs precoding may be referred to as a CAT-B O-RU.

[0067] Hereinafter, the term "upper PHY" refers to physical layer processing performed by the DU of the fronthaul interface. For example, the upper PHY may include FEC encoding / decoding, scrambling, and modulation / demodulation. Hereinafter, the term "lower PHY" refers to physical layer processing performed by the RU of the fronthaul interface. For example, the lower PHY may include FFT / iFFT, digital beamforming, and PRACH (physical random access channel) extraction and filtering. However, the above criteria do not exclude embodiments with other functional separations. The functional configurations, signaling, or operations shown in FIGS. 5A to 12B, which will be described later, can be applied to other functional separations as well as the third functional separation 420a or the fourth functional separation 420b.

[0068] In the embodiments of the present disclosure, the eCPRI and O-RAN standards are exemplarily described as fronthaul interfaces when transmitting messages between a DU (e.g., DU 210 in FIG. 2A ) and an RU (e.g., RU 220 in FIG. 2A ). The Ethernet payload of the message may include an eCPRI header, an O-RAN header, and additional fields. Hereinafter, various embodiments of the present disclosure will be described using terms from the eCPRI or O-RAN standards, but in various embodiments of the present disclosure, each term may be replaced with other expressions having equivalent meanings.

[0069] The Ethernet payload may contain an eCPRI header and an O-RAN header. The eCPRI header can be placed at the front end of the Ethernet payload. The contents of the eCPRI header are as follows:

[0070] 1) ecpriVersion (4 bits): This parameter refers to the eCPRI protocol version. 2) ecpriReserved (3 bits): This parameter is reserved for further use of eCPRI. 3) ecpriConcatenation (1 bit): This parameter indicates when eCPRI concatenation is being used. 4) ecpriMessage (1 byte): This parameter indicates the type of service carried by the message type. For example, the parameter indicates an IQ (in-phase and quadrature-phase) data message, a real-time control data message, or a transmission network delay measurement message. 5) ecpriPayload (2 bytes): This parameter indicates the byte size of the payload portion of the eCPRI message. 6) ecpriRtcid / ecpriPcid (2 bytes): This parameter is the eAxC (extended Antenna-carrier) identifier (eAxC ID) and identifies the specific data flow associated with each C-plane (ecpriRtcid) or U-plane (ecpriPcid) message. 7) ecpriSeqid (2 bytes): This parameter provides unique message identification and ordering on two levels. The first octet of this parameter is the sequence ID used to identify the order of messages in the eAxC message stream. The sequence ID is used to verify that all messages have been received and to reorder messages that are out of order. The second octet of this parameter is the subsequence ID. The subsequence ID is used to verify ordering and perform reordering when radio-transport-level (eCPRI or IEEE-1914.3) fragmentation occurs.

[0071] The eAxC identifier (ID) includes a band and sector identifier ("BandSector_ID"), a component carrier identifier ("CC_ID"), a spatial stream identifier ("RU_Port_ID"), and a distributed unit identifier ("DU_Port_ID"). The bit allocation of the eAxC ID can be distinguished as follows:

[0072] 1) DU_Port_ID: DU_Port_ID is used to distinguish processing units within the O-DU (e.g., other baseband cards). The O-DU allocates bits for DU_Port_ID, and the O-RU is expected to append the same value to UL U-plane messages carrying the same sectionId data. 2) BandSector_ID: Aggregated cell identifier (band and sector division supported by O-RU). 3) CC_ID: CC_ID distinguishes the carrier components supported by the O-RU. 4) RU_port ID: The RU_port ID specifies logical flows such as data layers or spatial streams, and signal channels that require special antenna allocation, such as separate numerologies (e.g., PRACH) or SRS.

[0073] The fronthaul application protocols may include a control plane (C-plane), a user plane (U-plane), a synchronization plane (S-plane), and a management plane (M-plane).

[0074] The control plane can be configured to provide scheduling information and beamforming information via control messages. The control plane refers to real-time control between the DU and the RU. The user plane can include IQ sample data transmitted between the DU and the RU. The user plane can include user downlink data (IQ data or SSB / RS), uplink data (IQ data or SRS / RS), or PRACH data. The weight vector of the beamforming information mentioned above can be multiplied by the user's data. The synchronization plane generally refers to traffic between the DU and the RU to a synchronization controller (e.g., an IEEE grandmaster). The synchronization plane can relate to timing and synchronization. The management plane refers to non-real-time control between the DU and the RU. The management plane can relate to initial setup, non-real-time reset or reset, and non-real-time reports.

[0075] Control plane messages, or C-plane messages, can be encapsulated based on a two-layer header approach. The first layer can consist of an eCPRI common header or an IEEE 1914.3 common header, which contains a field used to indicate the message type. The second layer is the application layer, which contains fields necessary for control and synchronization. Sections within the application layer define the characteristics of U-plane data transmitted and received on beams with one pattern ID. The supported section types within the C-plane are:

[0076] The section type may indicate the purpose of a control message transmitted on the control plane. For example, the purposes of each section type are as follows:

[0077] 1) sectionType=0: Used to refer to resource blocks or symbols that are not used in DL or UL. 2) sectionType=1: Used for most DL / UL radio channels, where "most" refers to channels that do not require a time or frequency offset, such as those required for mixed numerology channels. 3)sectionType=2:reserved for further use 4) sectionType=3: PRACH and mixed-numerology channels, if a time or frequency offset is required, or if the channel differs from the nominal SCS value 5)sectionType=4:reserved for further use 6) sectionType=5: UE scheduling information. Transmits UE scheduling information so that the RU can perform real-time BF weight calculation (O-RAN optional BF method) 7) sectionType=6: UE-specific channel information transmission. UE channel information is periodically transmitted so that the RU can perform real-time BF weight calculation (O-RAN optional BF method). 8) sectionType=7: Used for LAA support

[0078] C-plane messages can be exchanged between DUs (e.g., DU 210, O-DU 251) and RUs (e.g., RU 220, O-RU 253-1). The main purpose of C-plane messages is to transmit data-related control information (e.g., scheduling and beamforming commands) required for user data processing if the information is not provided via the M-plane. Messages may be transmitted separately for DL-related commands and UL-related commands. Below, in Figure 5A, C-plane messages for downlink are shown, and in Figure 5b, C-plane messages for uplink are shown.

[0079] 5A shows an example of a downlink (DL) message according to an embodiment. DU refers to the DU 210 in FIG. 2A. According to one embodiment, the DU 210 may include the O-DU 251. RU refers to the RU 220 in FIG. 2A. According to one embodiment, the RU 220 may include the O-RU 253-1.

[0080] Referring to FIG. 5A, in operation 501, the DU 210 may transmit a C-plane message to the RU 220. The RU 220 may receive the C-plane message from the DU 210. The C-plane message may be transmitted via a fronthaul interface. The C-plane message may be configured on a symbol-by-symbol basis. For example, each C-plane message may include scheduling information for downlink signals in one or more symbols. For example, a C-plane message may include scheduling for downlink signals from symbol #M to symbol #N (i.e., symbol #M, symbol #M+1, ..., symbol #N-1, symbol #N). The scheduling information may be referred to as a section. A DL C-plane message describing multiple symbols is required to arrive at the RU 220 a certain period before the end of the DL U-plane reception window for the indicated start symbol (e.g., startSymbolId).

[0081] A C-plane message may be associated with one or more layers. A layer may be associated with eAxC between the DU 210 and the RU 220. According to one embodiment, a C-plane message may be associated with one layer. The C-plane message may include scheduling information for a downlink data stream corresponding to the one layer. According to another embodiment, a C-plane message may be associated with multiple layers. The C-plane message may include scheduling information for downlink data streams corresponding to different layers.

[0082] In operation 503, the DU 210 may transmit a U-plane message for symbol #M to the RU 220. The DU 210 may transmit a U-plane message for each layer at symbol #M to the RU 220. The RU 220 may receive the U-plane message for symbol #M from the DU 210. The U-plane message may be transmitted via a fronthaul interface. The U-plane message may include an IQ sample of downlink data transmitted from an upper node to a UE at symbol #M via a radio access network. The RU 220 may transmit a U-plane message related to a layer corresponding to the antenna to the UE via an antenna.

[0083] In operation 505, the DU 210 may transmit a U-plane message for symbol #M+1 to the RU 220. The DU 210 may transmit a U-plane message for each layer to the RU 220 at symbol #M+1. The RU 220 may receive the U-plane message for symbol #M+1 from the DU 210. The U-plane message may be transmitted via a fronthaul interface. The U-plane message may include IQ samples of downlink data transmitted from an upper node to a UE via a radio access network at symbol #M+1. The RU 220 may transmit a U-plane message associated with a layer corresponding to the antenna to the UE via an antenna. Although not shown in FIG. 5A , according to one embodiment, the DU 210 may transmit a U-plane message for each of symbols #M+2, ..., symbol #N-1 to the RU 220. That is, through operations 503 to 507, the DU 210 may transmit a U-plane message to the RU 220, including a downlink signal scheduled based on the C-plane message.

[0084] In operation 507, the DU 210 may transmit a U-plane message at symbol #N to the RU 220. The DU 210 may transmit a U-plane message for each layer at symbol #N to the RU 220. The RU 220 may receive the U-plane message at symbol #N from the DU 210. The U-plane message may be transmitted via a fronthaul interface. The U-plane message may include IQ samples of downlink data transmitted from an upper node to a UE at symbol #N via a radio access network. The RU 220 may transmit a U-plane message related to a layer corresponding to the antenna to the UE via an antenna.

[0085] 5b shows an example of an uplink (UL) message according to an embodiment. The DU is exemplified by the DU 210 of FIG. 2A. According to one embodiment, the DU 210 may include the O-DU 251. The RU is exemplified by the RU 220 of FIG. 2A. According to one embodiment, the RU 220 may include the O-RU 253-1.

[0086] Referring to FIG. 5b, in operation 551, the DU 210 may transmit a C-plane message to the RU 220. The RU 220 may receive the C-plane message from the DU 210. The C-plane message may be transmitted via a fronthaul interface. The C-plane message may be configured on a symbol-by-symbol basis. For example, each C-plane message may include scheduling information for uplink signals in one or more symbols. For example, a C-plane message may include scheduling for uplink signals from symbol #M to symbol #N (i.e., symbol #M, symbol #M+1, ..., symbol #N-1, symbol #N). The scheduling information may be referred to as a section. A UL C-plane message describing multiple symbols is required to arrive at the RU 220 a certain period before the uplink signal sample that first arrives at the antenna of the RU 220 at a symbol (e.g., startSymbol).

[0087] A C-plane message may be associated with one or more layers. A layer may be associated with eAxC between the DU 210 and the RU 220. According to one embodiment, a C-plane message may be associated with one layer. The C-plane message may include scheduling information for an uplink data stream corresponding to the one layer. According to another embodiment, a C-plane message may be associated with multiple layers. The C-plane message may include scheduling information for uplink data streams corresponding to different layers.

[0088] In operation 553, the RU 220 may transmit a U-plane message at symbol #M to the DU 210. The RU 220 may receive a UL signal at symbol #M. The RU 220 may receive a UL signal associated with a layer corresponding to the antenna via an antenna. The RU 220 may generate IQ sample data for the UL signal received at symbol #M. The RU 220 may transmit a U-plane message for each layer to the DU 210 at symbol #M. The DU 210 may receive the U-plane message at symbol #M from the RU 220. The U-plane message may be transmitted via a fronthaul interface. The U-plane message may include IQ sample data of an uplink signal at symbol #M.

[0089] In operation 555, the RU 220 may transmit a U-plane message for symbol #M+1 to the DU 210. The RU 220 may receive a UL signal at symbol #M+1. The RU 220 may receive a UL signal associated with a layer corresponding to the antenna via an antenna. The RU 220 may generate IQ sample data for the UL signal received at symbol #M+1. The RU 220 may transmit a U-plane message for each layer to the DU 210 at symbol #M+1. The DU 210 may receive a U-plane message for symbol #M from the RU 220. The U-plane message may be transmitted via a fronthaul interface. The U-plane message may include IQ sample data of the uplink signal at symbol #M. Although not shown in FIG. 5b, according to one embodiment, the RU 220 may transmit a U-plane message for each of symbols #M+2, ..., symbol #N-1 to the DU 210. That is, through operations 553 to 557, the RU 220 can transmit to the DU 210 a U-plane message including the UL signal received in the section scheduled based on the C-plane message.

[0090] In operation 557, the RU 220 may transmit a U-plane message for symbol #N to the DU 210. The RU 220 may receive a UL signal for symbol #N. The RU 220 may receive a UL signal associated with a layer corresponding to the antenna via an antenna. The RU 220 may generate IQ sample data for the UL signal received for symbol #N. The RU 220 may transmit a U-plane message for each layer for symbol #N to the DU 210. The DU 210 may receive the U-plane message for symbol #N from the RU 220. The U-plane message may be transmitted via a fronthaul interface. The U-plane message may include IQ sample data of the uplink signal for symbol #N.

[0091] FIG. 6 shows an example of layer-specific resource allocation according to one embodiment. Resources may be allocated across multiple layers and multiple resource blocks (RBs) within a symbol. A DU (e.g., DU 210, O-DU 251) may perform resource allocation. A scheduler in the DU 210 may allocate resources for downlink transmission of an RU (e.g., RU 220, O-RU 253-1) or uplink transmission of a UE (e.g., terminal 120). The DU 210 may point to an allocated resource region via a C-plane message. IQ samples corresponding to the downlink transmission or the uplink transmission may be provided from the DU 210 to the RU 220 via a U-plane message. The U-plane message may include layer-specific IQ sample data (hereinafter, U-plane data) in the RU 220.

[0092] Referring to FIG. 6, the horizontal axis of the chart 600 represents the frequency domain. The vertical axis of the resource chart 600 represents layers. Resource allocation can be performed in RB units. U-plane messages are transmitted in resource blocks ("PRBs"), and data in each PRB can start on a byte boundary. Depending on the IQ bit width, if the end of the data in a PRB does not fall on a byte boundary, zero bits can be added until the byte boundary is reached. Below, we assume resource allocation in RB units in each layer.

[0093] Resource allocation can be performed for each layer within a certain region in the frequency domain. The certain region in the frequency domain may be indicated by section information of the C-plane message. For example, U-plane data of layer #0 can be allocated to RB#0 (601) and RB#1 (603). U-plane data of layer #1 can be allocated to RB#0 (601) and RB#1 (603). U-plane data of layer #2 can be allocated to RB#0 (601), RB#1 (603), and RB#2 (605). U-plane data of layer #3 can be allocated to RB#0 (601), RB#1 (603), and RB#2 (605). U-plane data of layer #4 can be allocated to RB#0 (601). U-plane data of layer #5 can be allocated to RB#0 (601), RB#1 (603), RB#2 (605), and RB#3 (607).

[0094] On the other hand, there exists an area that is not scheduled (hereinafter referred to as a non-scheduled area) for a certain period in the frequency domain. For example, RB#2 (605) and RB#3 (607) of layer #0 correspond to the non-scheduled area. RB#2 (605) and RB#3 (607) of layer #1 correspond to the non-scheduled area. RB#3 (607) of layer #2 corresponds to the non-scheduled area. RB#3 (607) of layer #3 corresponds to the non-scheduled area. RB#1 (603), RB#2 (605), and RB#3 (607) of layer #4 correspond to the non-scheduled area.

[0095] A DU (e.g., DU 210, O-DU 251) can provide UE-specific channel information. An RU (e.g., RU 220, O-RU 253-1) can calculate beamforming weights for co-scheduled UEs in a specific resource (e.g., slot) based on the channel information. An identifier associated with each data section (e.g., a user identifier (ueId) in a C-plane message) can be used for beamforming. If a channel-information-based beamforming method is used for at least one layer (or spatial stream), the DU 210 must use the same beamforming method for all layers (or spatial streams) of a specific time-frequency resource element. For example, section type 5 of a C-plane message can be used for scheduling information for the channel-information-based beamforming method. One or more identifiers (e.g., ueIds) may be associated with a section of a C-plane message. The DU 210 can provide scheduling information for each layer to the RU 220 via the corresponding ueId.

[0096] 7A-7B show examples of beamforming using non-scheduling layer indication according to one embodiment. The beamforming may include channel information-based beamforming. The DU 210 may provide scheduling information for each layer to an RU (e.g., RU 220, O-RU 253-1) via a corresponding ueId. In FIGS. 7A-7B, the resource allocation shown in FIG. 6 is assumed to explain the scheduling information using ueId.

[0097] 7A, the horizontal axis of the resource chart 700 represents the frequency domain. The vertical axis of the resource chart 700 represents the layer. UEIDs can be assigned on a section-by-section basis. For example, section 710 can include RB#0 (601), RB#1 (603), RB#2 (605), and RB#3 (607).

[0098] According to one embodiment, a group configuration for multiple ports can be used to indicate the section. For example, Section Extension 10 (SE10) of the O-RAN standard can be used in the C-plane message. C-plane section information for multiple ports (i.e., layers or Tx / Rx paths) can be identical except for the beam ID or UE ID. When multiple ports share common section information within the RU 220, the C-plane sections transmitted through those ports can be merged into one C-plane section through a representative port using SE10. For example, to merge the C-plane sections, section extension information such as the following table can be added to the C-plane message:

[0099] [Table 1]

[0100] "ef" may indicate the presence or absence of a section extension. For example, "ef" = 1 indicates the presence of a section extension field (section extension information), and "ef" = 0 indicates the absence of a section extension field. "extType" indicates the type of the section extension field, and "extLen" indicates the length in bytes of the section extension field. "numPortc" can indicate the number of ports (e.g., eAxC ports) (or the number of layers, the number of transmit / receive paths) indicated by the section extension field. For example, via 6 bits, "numPortc" can indicate up to 64 ports. "beamGroupType" can indicate the type of beam grouping. If "beamGroupType" is "00b", the beam ID in the section header can be used as a common beam ID for all ports. If "beamGroupType" is "01b", "numPortc" consecutive or non-consecutive beam IDs or ueIds following the beam ID or ueId in the section header can be applied to ports conforming to "numPortc". If "beamGroupType" is "10b", the "numPortc" number of consecutive or non-consecutive beam IDs or ueIds following the beam ID or ueId in the section header can be applied to ports that conform to "numPortc". If "beamGroupType" is "10b", the following table can be referenced.

[0101] [Table 2]

[0102] The section extension field may further include a beamID (or ueId) for "numPortc". A distinction between single user and multi-user can be made based on whether scheduling overlaps within a specified frequency region (e.g., one or more RBs). For example, the C-plane message to which Table 2 is added can provide resource allocation for multiple UEs within the same section. That is, the C-plane message may correspond to a multi-user schedule. The resource allocation in FIG. 6 is performed for six layers within the same section, but corresponds to MU-MIMO.

[0103] In chart 700, "numPortc" may be 5. Scheduling information for a total of six ports may be provided through the C-plane message. For example, the C-plane message may include a message format according to Section Type 5 and Section Extension 10 of the O-RAN standard. Each port may represent a layer of MU-MIMO. The DU 210 may assign a ueId to each layer among the layers for MU-MIMO. For example, in section 710, the ueId of layer #0 may be set to 1. In section 710, the ueId of layer #1 may be set to 2. In section 710, the ueId of layer #2 may be set to 10. In section 710, the ueId of layer #3 may be set to 11. In section 710, the ueId of layer #4 may be set to 24. In section 710, the ueId of layer #5 may be set to 30. At this time, a ueId can also be assigned to an area where there is no actual U-plane data (for example, RB#2 (605) of layer#0).

[0104] The RU 220 may receive the C-plane message. The RU 220 may identify the section 710. The RU 220 may identify the ueId corresponding to the section 710. The RU 220 may calculate beamforming weights for the ueId. For example, if K layers are commonly scheduled for MU-MIMO, a beamforming matrix W may be applied to frequency domain IQ data for the K layers. However, beamforming performed under the assumption that the same frequency region is assigned to each layer, even though the scheduled region for each layer is different, may result in degradation of beamforming performance.

[0105] In some frequency regions, at least one layer may not be scheduled. For example, in RB #0 (601), scheduling of all layers is performed, while in RB #2 (605), scheduling is performed for layer #2 of UE #2, layer #3 of UE #2, and layer #5 of UE #4. In this case, the DU 210 can provide scheduling information to the RU 220. However, if the DU 210 does not provide information (e.g., layer #0, layer #1, layer #4) about layers that are not scheduled in a specific frequency region (e.g., RB #2 (605)) to the RU 220, the RU 220 cannot know whether the specific region is not scheduled or whether it is scheduled but the RU 220 has not yet received the information. In RB #2 (605), assuming MU-MIMO beamforming for six layers as in RB #1, the beamforming weights are calculated based on both the unscheduled and scheduled layers.

[0106] Beamforming weights for six layers can be calculated across RB#0 (601), RB#1 (603), RB#2 (605), and RB#3 (607). Although RBs of some layers are not scheduled, they are included as elements for calculating beamforming weights. However, the beamforming weights may be derived in a manner that is not suitable for the actual scheduling results. Furthermore, since beamforming weights for more layers than the actual scheduled layers are calculated, the beamforming gain may be reduced. To solve the above problem, an electronic device and method according to an embodiment of the present disclosure propose a method for improving the accuracy of beamforming weights and increasing beamforming gain by indicating layers that are not scheduled (hereinafter referred to as non-scheduled layers) in MU-MIMO beamforming.

[0107] According to an embodiment, the DU 210 can transmit information to the RU 220 to indicate a non-scheduled layer in beamforming for MU-MIMO. According to an embodiment, a specific value of ueId in a C-plane message of section type 5 of the O-RAN standard can be used to indicate a non-scheduled layer. In the scheduling information of the C-plane message of section type 5, ueId can indicate a layer. Instead of indicating a layer scheduled for MU-MIMO in the section, ueId can indicate a non-scheduled layer. For example, ueId can be 16 bits. When the value of ueId is 0x7FFF (=2 15−1) (“111 1111 1111 1111b”), a non-scheduled layer can be indicated. The DU 210 can identify a non-scheduled layer, i.e., a non-scheduled layer, and set the ueId of the non-scheduled layer to 0x7FFF. The RU 220 can identify a layer corresponding to the ueId set to 0x7FFF. The identification can indicate that the RU 220 interprets the ueId set to 0x7FFF as meaning that the port is not scheduled. The RU 220 can perform beamforming based on identifying the absence of U-plane data for the identified layer. Even if the RU 220 receives a U-plane message for the layer from the DU 210, the RU 220 can ignore the U-plane data.

[0108] Referring to FIG. 7B, the horizontal axis of the chart 750 represents the frequency domain. The vertical axis of the resource chart 700 represents the layer. ueIds can be assigned on a layer and RB basis. RB#2 (605) and RB#3 (607) of layer #0 can be assigned ueId=0x7FFF. RB#2 (605) and RB#3 (607) of layer #1 can be assigned ueId=0x7FFF. RB#3 (607) of layer #2 can be assigned ueId=0x7FFF. RB#3 (607) of layer #3 can be assigned ueId=0x7FFF. RB#1 (603), RB#2 (605), and RB#3 (607) of layer #4 can be assigned ueId=0x7FFF.

[0109] According to one embodiment, the DU 210 can indicate non-scheduled layers to the RU 220 via section extension information of the C-plane message. For example, the DU 210 can send a C-plane message for layers #0 to #5 to the RU 220. The C-plane message may include scheduling information for RB #2 (605). The section extension information of the C-plane message may include "numPortc=5" and include five ueIds. The ueId and the additional five ueIds included in the section field of the C-plane message may indicate layers #0, #1, #2, #3, #4, and #5, respectively. Each of the non-scheduled layers may have a predefined value. The ueId value for layer #0 may be "0x7FFF". The ueId value for layer #1 may be "0x7FFF". The ueId value for layer #4 may be "0x7FFF". Each actual scheduled layer may have a unique ueId value. The value of the ueId for Layer #2 may be "0x000A". The value of the ueId for Layer #3 may be "0x000B". The value of the ueId for Layer #5 may be "0x001E".

[0110] According to another embodiment, the DU 210 can indicate non-scheduled layers by transmitting a layer-specific C-plane message to the RU 220. For example, the DU 210 can transmit a C-plane message for layer #0 to the RU 220. Information in the header of the C-plane message (e.g., eAxC ID) can indicate layer #0. A section of the C-plane message can point to RB #2 (605) and RB #3 (607), and the ueId of the C-plane message can be set to 0x7FFF. In this way, non-scheduled regions for each of layer #1, layer #2, layer #3, and layer #4 can be indicated.

[0111] For MU-MIMO, the RU 220 can calculate beamforming weights based on jointly scheduled layers. The beamforming weights include a beamforming matrix and can be applied to IQ data in the frequency domain. The RU 220 can identify non-scheduled layers. The RU 220 can calculate beamforming weights based on at least one layer different from the non-scheduled layers. For example, the RU 220 can calculate beamforming weights 761 based on six ueIds in RB#0 (601). MU-MIMO beamforming can be performed for six layers in RB#0 (601).

[0112] The RU 220 can calculate beamforming weights 763 in RB #1 (603) based on the five ueIds. In RB #1 (603), layer #4 may be designated as a non-scheduling layer. Here, the beamforming weights of layer #4 are not set to "0". This means that before calculating the beamforming weights, the ueId for layer #4 is excluded from the array elements for calculating the beamforming weights. Therefore, the weight of layer #4 is not calculated. Then, the RU 220 can calculate beamforming weights 763 for the five layers. In RB #1 (603), MU-MIMO beamforming can be performed for the five layers.

[0113] The RU 220 can calculate beamforming weights 765 in RB #2 (605) based on the three ueIds. In RB #2 (605), layers #0, #1, and #4 may be designated as non-scheduled layers. Here, the beamforming weight of layer #4 is not set to "0." This means that before calculating the beamforming weights, the ueId for layer #4 is excluded from the array elements for calculating the beamforming weights. Therefore, the beamforming weights for layers #0, #1, and #4 are not calculated. Then, the RU 220 can calculate beamforming weights 765 for the three layers. In RB #1 (603), MU-MIMO beamforming can be performed for the three layers.

[0114] The RU 220 can calculate beamforming weights 767 in RB #3 (607) based on the ueId of layer #5. The RU 220 can calculate the beamforming weights assuming a single user, rather than MU-MIMO beamforming.

[0115] In FIG. 7B, a predefined value of ueId is 0x7FFF (=2) to indicate a non-scheduled layer. 15 Although a value indicating a non-scheduled layer is shown as 0x0FF (=255), embodiments of the present disclosure are not limited thereto. For example, the value indicating a non-scheduled layer may be defined as another value (e.g., 0x0FF (=255)). Furthermore, although FIG. 7B describes that the value indicating a non-scheduled layer is defined in advance according to a standard, embodiments of the present disclosure are not limited thereto. For example, the value indicating a non-scheduled layer may be defined based on an M-plane parameter.

[0116] 8 illustrates an example of beamforming weights for each resource region according to an embodiment. To illustrate the applied beamforming weights, the resource allocation shown in FIG. 6 and the ueId of FIG. 7B are assumed in FIG. 8.

[0117] Referring to FIG. 8, a chart 800 shows beamforming weights per RB. The beamforming weights may include a beamforming matrix. The beamforming matrix may be calculated based on channel information according to a specified criterion (e.g., minimum mean square error (MMSE), zero forcing (ZF)). The beamforming matrix may include factors for each layer. For example, in RB#0 (601), the RU 220 assigns beamforming weight 761 (W RB0 ) can be obtained. The beamforming weight 761 (W RB0 ) is a matrix consisting of six channel information [h1h2h 10 h 11 h 24 h 30 ] as input. Each channel information corresponds to a scheduled ueId.

[0118] In a non-scheduled layer, i.e., an RB where a non-scheduled layer exists, the beamforming weights can be calculated in a different manner. In the method of calculating the beamforming weights according to the instruction of the non-scheduled layer according to the embodiment of the present disclosure, the non-scheduled layer is not considered as a placement element for the beamforming matrix. For example, in RB#1 (603), the RU 220 can obtain the beamforming weight 763. The beamforming weight 763 (W RB1 ) is a matrix consisting of five channel information [h1h2h 10 h 11 h 30 ] is input and calculated. Layer #4 is not scheduled, so the channel information of layer #4, h 24It is not provided as an input to the calculation of the beamforming weights 763. Furthermore, for example, in RB#2 (605), the RU 220 can obtain the beamforming weights 765. RB1 ) is a matrix consisting of three channel information [h1h2h 10 h 11 h 30 ] is received as input and calculated. Each channel information corresponds to a scheduled ueId. Since Layer #0, Layer #1, and Layer #4 are not scheduled, the channel information of Layer #0, Layer #1, and Layer #4, h1, h2, h 24 is also not provided as an input to the calculation of the beamforming weights 763.

[0119] When the number of layers scheduled by the non-scheduled layer is one, the C-plane message formally represents MU-MIMO beamforming, but the actually calculated beamforming weights may represent SU-MIMO beamforming. For example, in RB#3 (607), the RU 220 may obtain beamforming weight 767. The beamforming weight 763 (W RB3 ) is the channel of the scheduled ueId, h 30 Since Layer #0, Layer #1, Layer #2, Layer #3, and Layer #4 are not scheduled, among the layers configured for MU-MIMO beamforming (Layer #0, Layer #1, Layer #2, Layer #3, Layer #4, and Layer #5), the channel information scheduled for Layer #5, h 30 Only σ 1 , σ 2 , σ 3 , σ 4 , σ 5 , σ 6 , σ 7 , σ 8 , σ 9 , ...1 , σ 2 , σ 3 , σ 4 , σ 5 , σ 6 , σ 7 , σ 6 , σ 7 , σ 8 , σ 7 , σ 8 , σ 9 , σ 1 , σ 2 , σ 3 , σ

[0120] Since different scheduling results are used for each RB, beamforming weights can be calculated differently for each RB. Furthermore, as described for each RB in Figure 8, channel information corresponding to non-scheduled layers is not used as input for calculating beamforming weights. Non-scheduled layers are different from nulling layers in that only beamforming weights are calculated for layers to which U-plane data is not assigned by intentionally scheduling only the C-plane ueId without allocating U-plane data due to interference after scheduling. Furthermore, because beamforming weights are not allocated to unnecessary layers, the beamforming gain can be increased.

[0121] 9 shows a functional configuration of a DU and a RU for beamforming using instructions from a non-scheduling layer according to one embodiment. The DU refers to the DU 210 in FIG. 2A. According to one embodiment, the DU 210 may include an O-DU 251. The RU refers to the RU 220 in FIG. 2A. According to one embodiment, the RU 220 may include an O-RU 253-1.

[0122] Referring to FIG. 9, the DU 210 may include a scheduler 901, a modem 903, a C-plane processing unit 910a, and a U-plane processing unit 920a. The scheduler 901 may perform resource allocation. Resource allocation refers to scheduling of U-plane data, i.e., signals transmitted over a radio access network. Resource allocation may be performed in units of layers and RBs. The ueId of a C-plane message in Section Type 5 of the O-RAN standard may refer to the ueId assigned to a layer. According to one embodiment, the scheduler 901 may perform resource allocation based on the ueId. Resource allocation results may be distinguished by the ueId. According to one embodiment, a specific value of the ueId in a specific RB region may be used to indicate an unscheduled layer. For example, a ueId of 0x7FFF may indicate an unscheduled layer.

[0123] The modem 903 may perform modulation and demodulation on signals transmitted over the radio access network. The modem 903 may receive scheduled signals from the scheduler 901. The modem 903 may generate IQ sample data corresponding to the scheduled signals. The signals may be provided to the RU 220 over the fronthaul interface in the form of U-plane messages. The modem 903 may provide the IQ sample data to the U-plane processing unit 920a.

[0124] The C-plane processing unit 910a may generate a C-plane message. The C-plane processing unit 910a may generate the C-plane message based on a scheduling result received from the scheduler 901. According to one embodiment, the C-plane processing unit 910a may generate a C-plane message including a ueId for indicating an unscheduled layer. The C-plane processing unit 910a may transmit the C-plane message to the RU 220. The C-plane processing unit 910a may transmit the C-plane message to the C-plane processing unit 910b of the RU 220. The C-plane message may be provided over a fronthaul interface between the DU 210 and the RU 220.

[0125] The U-plane processing unit 920a may generate a U-plane message. The U-plane processing unit 920a may obtain IQ sample data from the modem 903. The U-plane processing unit 920a may generate a U-plane message including the IQ sample data. The U-plane processing unit 920a may transmit the U-plane message to the RU 220. The U-plane processing unit 920a may transmit the U-plane message to the U-plane processing unit 920b of the RU 220. The U-plane message may be provided on a fronthaul interface between the DU 210 and the RU 220.

[0126] The RU 220 may include a C-plane processing unit 910b, a U-plane processing unit 920b, a beamforming weight generation unit 930, and a beamforming unit 940.

[0127] The C-plane processing unit 910b can receive a C-plane message from the DU 210. The C-plane processing unit 910b can receive a C-plane message from the C-plane processing unit 910a of the DU 210. The C-plane processing unit 910b can process the received C-plane message. According to an embodiment, the C-plane processing unit 910b can identify scheduling information in the C-plane message. The C-plane processing unit 910b can identify whether or not layer-specific scheduling occurs in a specified frequency region (e.g., RB). The C-plane processing unit 910b can provide the scheduling result to the beamforming weight generation unit 930. The C-plane processing unit 910b can provide the ueId and information related to the ueId to the beamforming weight generation unit 930.

[0128] The U-plane processing unit 920b can receive a U-plane message from the DU 210. The U-plane processing unit 920b can receive a U-plane message from the U-plane processing unit 920a of the DU 210. The U-plane processing unit 910b can process the received U-plane message. The U-plane processing unit 920b can provide IQ sample data of the U-plane message to the beamforming weight generation unit 930.

[0129] The beamforming weight generator 930 may calculate beamforming weights. The beamforming weights may be calculated in the RU 220 based on channel estimates. According to one embodiment, the beamforming weight generator 930 may be configured not to generate beamforming weights for non-scheduled layers. The beamforming weight generator 930 may identify scheduled layers. The beamforming weight generator 930 may identify non-scheduled layers. According to one embodiment, the beamforming weight generator 930 may identify non-scheduled layers based on the value of ueId. If ueId is set to a specified value (e.g., 0x7FFF or 0x00FF (=2)) for non-scheduled layers, the beamforming weight generator 930 may generate beamforming weights for non-scheduled layers. 8 −1) (“000 0000 1111 1111”)), the beamforming weight generator 930 can identify that the layer in question is not scheduled within the C-plane section. Even if multiple layers for MU-MIMO are configured via the C-plane, the beamforming weight generator 930 can calculate beamforming weights only for at least one scheduled layer, rather than calculating beamforming weights for the multiple layers. In other words, non-scheduled layers are not included as array elements of the beamforming weight matrix.

[0130] The beamforming unit 940 may perform beamforming. The beamforming unit 940 may apply beamforming weights. The beamforming weights may be applied to frequency-domain IQ data for one or more layers. The beamforming weights may be applied to IQ sample data of a U-plane message. The RU 220 may transmit a downlink signal to which the beamforming weights have been applied via the beamforming unit 940. For example, the RU 220 may transmit a downlink signal to a UE (e.g., terminal 120).

[0131] Although processing of DL U-plane data has been described as an example in FIG. 9 , embodiments of the present disclosure are not limited thereto. Embodiments of the present disclosure may also be applied to processing of UL U-plane data. According to one embodiment, the U-plane processing unit 920a of the DU 210 may receive a U-plane message from the U-plane processing unit 920b of the RU 220. The U-plane message may include IQ sample data for an uplink signal.

[0132] 10 illustrates an operation flow of a DU for instructing a non-scheduling layer according to one embodiment. The DU represents the DU 210 in FIG. 2A. According to one embodiment, the DU 210 may comprise an O-DU 251.

[0133] 10 , in operation 1001, the DU 210 can identify non-scheduling for a layer within a resource region. The resource region is a time-frequency resource and can refer to an RB region corresponding to a symbol. The resource region may be referred to as a data section. The DU 210 can identify a layer that is not scheduled in the RB region, i.e., a non-scheduled layer.

[0134] In operation 1003, the DU 210 may generate a C-plane message including information about a resource region and UE identification information corresponding to a value for indicating non-scheduling for a layer. The information about the resource region may include section information indicating an RB region corresponding to a symbol. The C-plane message may indicate the resource region via the position of the starting PRB (e.g., startPrbc) and the number of consecutive PRBs (e.g., numPrbc). The UE identification information may be used for channel information-based beamforming. For scheduling of MU-MIMO beamforming, individual layers may correspond to UE identification information. The UE identification information may include a ueId parameter for providing a label for the UE to which the section content applies. For example, the ueId parameter may be configured with 15 bits. According to one embodiment, the UE identification information may indicate a predefined value to indicate non-scheduling of a layer, or may indicate a pre-configured value (e.g., an M-plane parameter) to indicate non-scheduling of a layer. For example, a value of 0x7FFF for the ueId parameter may indicate non-scheduling of the layer corresponding to the ueId parameter. The RU 220 can interpret a ueId set to 0x7FFF as meaning that the port is not scheduled. The RU 220 can identify that the resource region of the port with a ueId set to 0x7FFF is not allocated. In another example, if the last 8 bits of the ueId parameter indicate 255, non-scheduling of the layer corresponding to the ueId parameter can be indicated.

[0135] According to one embodiment, a C-plane message may be transmitted for each layer. The C-plane message may include scheduling information for the corresponding layer. For example, the C-plane message may have a message format of Section Type 5 of the O-RAN standard. Channel information related to the UE identity may be used to calculate beamforming weights for the layer. A C-plane message different from the C-plane message including scheduling information may be associated with a non-scheduled layer. The C-plane message may include a ueId parameter included in the section information of the C-plane message of Section Type 5 to indicate non-scheduling. The C-plane message may indicate a non-scheduled region.

[0136] According to another embodiment, a C-plane message may include scheduling information for multiple layers. For example, the C-plane message may have a message format of Section Type 5 of the O-RAN standard. Furthermore, the C-plane message may include section extension information (e.g., SE10 of the O-RAN standard) for group configuration of multiple ports. The C-plane message may include UE identification information for each of multiple layers within the same resource region. In this case, a ueId parameter of the UE identification information associated with a non-scheduled layer may indicate non-scheduling. For example, if the non-scheduled layer is the first layer, the ueId of the section information of the C-plane message may indicate non-scheduling. Furthermore, for example, if the non-scheduled layer is not the first layer, a ueId corresponding to the order of the non-scheduled layer in the section extension information of the C-plane message may indicate non-scheduling.

[0137] In operation 1005, the DU 210 may transmit a C-plane message. The DU 210 may transmit the C-plane message to the RU 220 via a fronthaul interface. The C-plane message may be used for calculation of beamforming weights for beamforming in the RU 220.

[0138] Although not shown in Fig. 10, a U-plane message for transmitting a signal in a region scheduled by a C-plane message can be transmitted over the fronthaul interface. For example, in the case of downlink transmission, the DU 210 can transmit a U-plane message corresponding to a layer other than the non-scheduled layer to the RU 220 within the resource region of the C-plane. Furthermore, for example, in the case of uplink transmission, the DU 210 can receive a U-plane message corresponding to a layer other than the non-scheduled layer from the RU 220 within the resource region of the C-plane.

[0139] The indication of non-scheduled layers can be used by the RU 220 to calculate beamforming weights to be applied to signals transmitted over the radio access network. Since the indicated non-scheduled layers are excluded from the beamforming weight calculation, beamforming weights appropriate for the actual scheduling can be obtained. Furthermore, since allocations to unnecessary layers are not considered, the beamforming gain can be increased.

[0140] 11 illustrates an operation flow of an RU for instructing a non-scheduling layer according to one embodiment. The RU represents the RU 220 of FIG. 2A. According to one embodiment, the RU 220 may include an O-RU 253.

[0141] Referring to FIG. 11 , in operation 1101, the RU 220 may receive a C-plane message including information about a resource region and UE identification information corresponding to a value for indicating non-scheduling for a layer. The information about the resource region may include section information indicating an RB region corresponding to a symbol. The C-plane message may indicate the resource region via the position of the starting PRB (e.g., startPrbc) and the number of consecutive PRBs (e.g., numPrbc). The UE identification information may be used for channel information-based beamforming. For scheduling of MU-MIMO beamforming, individual layers may correspond to UE identification information. The UE identification information may include a ueId parameter for providing a label for the UE to which the section content applies. For example, the ueId parameter may be configured with 15 bits. According to one embodiment, the UE identification information may indicate a predefined value to indicate non-scheduling of a layer, or may indicate a pre-configured value (e.g., an M-plane parameter) to indicate non-scheduling of a layer. For example, a value of 0x7FFF for the ueId parameter may indicate non-scheduling of the layer corresponding to the ueId parameter. In another example, if the last 8 bits of the ueId parameter indicate 255, it can indicate non-scheduling of the layer corresponding to the ueId parameter.

[0142] In operation 1103, the RU 220 may calculate beamforming weights based on the C-plane message. The RU 220 may identify non-scheduled layers based on the C-plane message. The RU 220 may identify at least one scheduled layer based on the C-plane message or another C-plane message. The RU 220 may calculate beamforming weights for the at least one scheduled layer by excluding the non-scheduled layers. That is, the non-scheduled layers are not used as inputs for calculating beamforming weights.

[0143] According to one embodiment, a C-plane message may be transmitted for each layer. To calculate beamforming weights for a layer, channel information associated with the UE identity corresponding to the layer may be utilized. For example, the C-plane message may have a message format of Section Type 5 of the O-RAN standard. A C-plane message for at least one layer may indicate scheduling of the corresponding layer within the section. A C-plane message for a non-scheduling layer may indicate non-scheduling within the section. A ueId parameter included in the section information of a C-plane message for a non-scheduling layer may indicate non-scheduling. The section of the C-plane message may be a non-scheduling region.

[0144] According to another embodiment, a C-plane message may include scheduling information for multiple layers. For example, the C-plane message may have a message format of Section Type 5 of the O-RAN standard. Furthermore, the C-plane message may include section extension information (e.g., SE10 of the O-RAN standard) for group configuration of multiple ports. The C-plane message may include UE identification information for each of multiple layers in the same resource region. In this case, a ueId parameter of the UE identification information associated with a layer that is not scheduled may indicate non-scheduling.

[0145] The RU 220 may calculate beamforming weights based on scheduled layers, excluding non-scheduled layers, within a specific resource region. The beamforming weights refer to an arrangement for at least one scheduled layer. The arrangement may include weight values ​​to be applied to IQ data of each layer. The size of the arrangement corresponds to the number of the at least one scheduled layer. Therefore, even if a C-plane message indicates six layers, if the UE identification information for one layer indicates the one layer as a non-scheduled layer, the beamforming weight W may include weight values ​​for each of the five layers.

[0146] The RU 220 can calculate beamforming weights based on channel information. For example, the RU 220 can calculate beamforming weights based on periodically provided channel information (e.g., channel information of a C-plane message of section type 6). Furthermore, for example, the RU 220 can calculate beamforming weights based on the channel information and scheduling information (e.g., section information of a C-plane message of section type 5). The RU 220 can calculate beamforming weights based on channel information of a scheduled layer. In this case, if the value of ueId indicates non-scheduling, the RU 220 may ignore the channel information of the layer corresponding to the ueId. If the value of ueId does not indicate non-scheduling, the RU 220 can calculate beamforming weights based on the channel information of the layer corresponding to the ueId.

[0147] In operation 1105, the RU 220 may perform beamforming. The RU 220 may perform beamforming based on the calculated beamforming weights. The RU 220 may transmit a downlink signal via beamforming. The downlink signal may be transmitted on radio resources scheduled via a C-plane message. IQ sample data for the downlink signal may be provided to the RU 220 via a per-layer U-plane message. The RU 220 may receive a U-plane message from the DU 210. A weight value corresponding to a specific layer may be applied to the IQ sample data of the U-plane message corresponding to the specific layer. Here, the specific layer may be associated with a ueId. According to an embodiment, if the ueId indicates non-scheduling, the RU 220 may not receive a U-plane message corresponding to the layer of the ueId, or may ignore or discard the received U-plane message.

[0148] 11 illustrates beamforming by the RU 220 assuming downlink transmission, but the embodiments of the present disclosure are not limited thereto. The non-scheduling layer instructions can also be applied to beamforming of UL signals. Based on the non-scheduling layer instructions, beamforming matrices can be calculated for UEs jointly scheduled for MU-MIMO.

[0149] 12B-12C illustrate examples of C-plane messages for indicating a non-scheduling layer according to one embodiment. The C-plane messages may have a message format according to Section Type 5 of the O-RAN standard. In FIG. 12B, a C-plane message 1200 for indicating a non-scheduling layer is described when an SE 10 of the O-RAN standard is not used. In FIG. 12B, a C-plane message for indicating a non-scheduling layer is described when an SE 10 of the O-RAN standard is used.

[0150] 12B, a C-plane message 1200 can include a transport header (e.g., eCPRI header or IEEE 1914.3) information. The transport header can include the aforementioned "ecpriVersion," "ecpriReserved," "ecpriConcatenation," "ecpriMessage," "ecpriPayload," "ecpriRtcid / ecpriPcid," and "ecpriSeqid."

[0151] The C-plane message 1200 may include common header information, such as "dataDirection" indicating the data transmission direction of the base station (e.g., gNB), "payloadVersion" indicating the valid payload protocol version of the IE at the application layer, and "filterindex" representing the index of the channel filter between the IQ data and the air interface, used in both DL and UL.

[0152] The common header information can include information for indicating the location of the time resource to which the message is applicable. The location of the time resource can be indicated by frame, subframe, slot, or symbol. The common header information can include "frameId" indicating the frame number, "subframeId" indicating the subframe number, "slotId" indicating the slot number, and "startSymbolId" indicating the symbol number. The frame is determined based on a 256-modulus operation. The subframe has a unit of 1 ms contained in a 10 ms frame. The slot numbers are numbered within the subframe, and the maximum size can be 1, 2, 4, 8, or 16 depending on the pneumology.

[0153] The common header information may include "numberOfsections", which indicates the number of data sections included in the C-plane message 1200. The common header information may include "sectionType", which determines the characteristics of the U-plane data. The common header information may include the number of sections in the sample (e.g., T s = 1 / 30.72 MHz (megahertz)) and may include a "timeoffset" that defines the offset from the start of the slot to the start of the cyclic prefix (CP). The common header information may include a "frameStructure" that defines the FFT (fast fourier transfer) / iFFT (inverse FFT) size and SCS. The common header information may include the number of samples (e.g., T s= 1 / 30.72 MHz (megahertz), and may include "cpLength" which defines the CP length.

[0154] The C-plane message 1200 may include section information. The section information may include a "sectionId" that stands for a section identifier. When C-plane and U-plane coupling via "sectionId" is used, the "sectionId" identifies an individual data section described by a data section description in the C-plane message 1200. The purpose of the "sectionId" is to map a U-plane data section to the corresponding C-plane message 1200 (and section type) associated with the data. The section information may include 'rb' indicating whether all RBs are used (every RB is used) or every other RB is used, 'symInc' meaning a symbol number increment command, 'startPrbc' for indicating the start PRB number of the data section description, 'numPrbc' for indicating the number of consecutive PRBs per data section description, 'reMask' defining an RE mask within the PRB, 'numSymbol' defining the number of PRACH (physical random access channel) repetitions or the number of symbols, 'ef' for indicating an extension flag, and 'ueId' defining the beam pattern to be applied to U-plane data.

[0155] In the channel information-based beamforming method, the DU 210 can provide channel information for each UE periodically (typically less often than every slot) using a section type 6 C-plane message. Then, on a slot-by-slot basis, the DU 210 can provide scheduling information using a section type 5 C-plane message to be used with the channel information. The RU 220 can calculate appropriate beamforming weights for the jointly scheduled UE and the specific slot. For channel information-based beamforming operations, the RU 220 can utilize the latest channel information available for the ueId. That is, the RU 220 can use the channel information for the 'ueId' available to the RU 220 at the end of the reception window of the section type 5 C-plane message.

[0156] Assume layer #2 in the resource allocation shown in FIG. 6. Layer #2 is scheduled in RB #0 (601), RB #1 (603), and RB #2 (605), and is not scheduled in RB #3 (607). Therefore, a C-plane message may include two sections for layer #2. The first section of layer #2 (e.g., sectionId = xx) may include RB #0 (601), RB #1 (603), and RB #2 (605). To indicate RB #0 (601), RB #1 (603), and RB #2 (605), startPRBc may point to 0 and numPrbc may point to 3. The second section of layer #2 (e.g., sectionId = xx + 1) may include RB #3 (607). To indicate RB #3 (607), startPRBc may point to 3 and numPrbc may point to 1. Here, since the first section is a scheduled region, the ueId value can be assigned to 11. For example, ueId[14:0] may indicate “11.” However, since the second section is an unscheduled region, the ueId value can be set to a value to indicate a non-scheduled layer. According to one embodiment, the DU 210 can set the ueId value to a value defined for a non-scheduled layer. For example, ueId[14:0] may indicate “0x7FFF.” In another example, ueId[14:0] may indicate “255.” According to another embodiment, the DU 210 can set some fields of the ueId bits (e.g., 8 least significant bits) to specific values ​​to indicate a non-scheduled layer. The DU 210 can use some bits instead of using the entire 15 bits for the ueId. For example, ueId[7:0] may indicate “255.”

[0157] 12B, the C-plane message 1250 may include a transmission header (e.g., eCPRI header or IEEE 1914.3) information. The C-plane message 1250 may include common header information. The C-plane message 1250 may also include section information. For the separate fields of the transmission header information, common header information, and section information of the C-plane message 1250, please refer to the description of the C-plane message 1200 in FIG. 12B.

[0158] The C-plane message 1250 may include section extension information. The section extension information may have a format according to the SE10. For example, the section extension information may have a format as shown in Table 2. Assume RB#1 (603) in the resource allocation shown in FIG. 6. For common resource allocation for layers in RB#1 (603), the C-plane message 1250 including the section extension information by the SE10 can be provided to the RU 220. The DU 210 may indicate scheduling information for the first layer (e.g., layer #0) of the six layers in RB#1 (603) via the section information of the C-plane message 1250. Scheduling information for the remaining layers (e.g., layer #1, layer #2, layer #3, layer #4, layer #5) may be indicated via the section extension information of the C-plane message 1250. The remaining layers may be indicated via the section extension information of the C-plane message 1250. nd port ueId, 3 rd port ueId, 4 th Port ueId, 5 th port ueId, and 6 th They can be assigned to port ueIds respectively.

[0159] In RB#1 (603), UE#3 is not scheduled. In other words, RB#1 (603) of Layer#4 is a non-scheduling region. To indicate a non-scheduling region in RB#1 (603), ueId can be set to a specified value. According to one embodiment, the DU 210 can set the value of ueId to a value defined for a non-scheduling layer. For example, ueId[14:0] can point to "0x7FFF". In another example, ueId[14:0] can point to "255". According to another embodiment, the DU 210 can set some fields of bits of ueId (e.g., the 8 least significant bits (LSBs)) to specific values ​​to indicate a non-scheduling layer. The DU 210 can use some bits instead of using all 15 bits for ueId. For example, ueId[7:0] can point to "255".

[0160] In an embodiment, an electronic device of a radio unit (RU) may include at least one fronthaul transceiver, at least one radio frequency (RF) transceiver, and at least one processor coupled to the at least one fronthaul transceiver and the at least one RF transceiver. The at least one processor may be configured to receive a control plane (C-plane) message from a distributed unit (DU) via a fronthaul interface, the control plane (C-plane) message including information regarding a resource region and user equipment (UE) identification information corresponding to a value for indicating non-scheduling of a layer. The at least one processor may be configured to calculate beamforming weights based on the C-plane message. The at least one processor may be configured to perform beamforming based on the beamforming weights.

[0161] According to one embodiment, the beamforming weights may be a configuration for at least one layer scheduled in the resource region. This configuration may include weight values ​​to be applied to in-phase and quadrature-phase (IQ) data in each layer. The size of the configuration may correspond to the number of the at least one layer. The at least one layer may not include the layer for which the non-scheduling is indicated.

[0162] According to one embodiment, the beamforming weights may be calculated based on channel information received from the DU.

[0163] According to one embodiment, the C-plane message may include section extension information for a group configuration of multiple ports. The section extension information may include UE identification information for each additional layer. The additional layer may include the layer for which the non-scheduling is indicated, and the UE identification information for the layer may be included in the section extension information.

[0164] According to one embodiment, the UE identification information may include a ueId parameter for providing a label of the UE to which the section content applies. The ueId parameter is 15 bits, and the value indicating non-scheduling may be 0x7FFF, 0x00FF, or a value set by the M-plane.

[0165] In one embodiment, an electronic device of a distributed unit (DU) may include at least one transceiver and at least one processor coupled to the at least one transceiver. The at least one processor may be configured to identify non-scheduling for a layer in a resource region. The at least one processor may be configured to generate a control plane (C-plane) message including information about the resource region and user equipment (UE) identification information corresponding to a value for indicating the non-scheduling for the layer. The at least one processor may be configured to transmit the generated C-plane message to a radio unit (RU). The C-plane message may be associated with beamforming weights for the RU.

[0166] According to one embodiment, the beamforming weights may be a constellation for at least one layer scheduled in the resource region. The constellation may include weight values ​​to be applied to in-phase and quadrature-phase (IQ) data in each layer. The size of the constellation may correspond to the number of the at least one layer. The at least one layer may not include the layer for which the non-scheduling is indicated.

[0167] According to one embodiment, the at least one processor may be configured to transmit channel information to the RU, the channel information being usable for the beamforming weights.

[0168] According to one embodiment, the C-plane message may include section extension information for a group configuration of multiple ports. The section extension information may include UE identification information for each additional layer. The additional layer may include the layer for which the non-scheduling is indicated, and the UE identification information for the layer may be included in the section extension information.

[0169] According to one embodiment, the UE identification information may include a ueId parameter for providing a label of the UE to which the section content applies. The ueId parameter is 15 bits, and the value indicating non-scheduling may be 0x7FFF, 0x00FF, or a value set by M-Plane. In an embodiment, a method performed by a radio unit (RU) may include receiving, via a fronthaul interface, a control plane (C-plane) message from a distributed unit (DU) including information regarding a resource region and user equipment (UE) identification information corresponding to a value for indicating non-scheduling of a layer. The method may include calculating beamforming weights based on the C-plane message. The method may include performing beamforming based on the beamforming weights.

[0170] According to one embodiment, the beamforming weights may be a configuration for at least one layer scheduled in the resource region. The configuration may include weight values ​​to be applied to in-phase and quadrature-phase (IQ) data in each layer. The size of the configuration may correspond to the number of the at least one layer. The at least one layer may not include a layer for which non-scheduling is indicated.

[0171] According to one embodiment, the beamforming weights may be calculated based on channel information received from the DU.

[0172] According to one embodiment, the C-plane message may include section extension information for a group configuration of multiple ports. The section extension information may include UE identification information for each additional layer. The additional layer may include the layer for which the non-scheduling is indicated, and the UE identification information for the layer may be included in the section extension information.

[0173] According to one embodiment, the UE identification information may include a ueId parameter for providing a label of the UE to which the section content applies. The ueId parameter is 15 bits, and the value indicating non-scheduling may be 0x7FFF, 0x00FF, or a value set by the M-plane.

[0174] In an embodiment, a method performed by a distributed unit (DU) can include an act of identifying non-scheduling for a layer in a resource region. The method can include an act of generating a control plane (C-plane) message including information about the resource region and user equipment (UE) identification information corresponding to a value indicating the non-scheduling for the layer. The method can include an act of transmitting the generated C-plane message to a radio unit (RU). The C-plane message can be associated with beamforming weights for the RU.

[0175] According to one embodiment, the beamforming weights may be a configuration for at least one layer scheduled in the resource region. This configuration may include weight values ​​to be applied to in-phase and quadrature-phase (IQ) data in each layer. The size of the configuration may correspond to the number of the at least one layer. The at least one layer may not include the layer for which the non-scheduling is indicated.

[0176] According to one embodiment, the method can include the at least one processor transmitting channel information to the RU, the channel information being usable for the beamforming weights.

[0177] According to one embodiment, the C-plane message may include section extension information for a group configuration of multiple ports. The section extension information may include UE identification information for each additional layer. The additional layer may include the layer for which the non-scheduling is indicated, and the UE identification information for the layer may be included in the section extension information.

[0178] According to one embodiment, the UE identification information may include a ueId parameter for providing a label of the UE to which the section content applies. The ueId parameter is 15 bits, and the value indicating non-scheduling may be 0x7FFF, 0x00FF, or a value set by M-Plane.

[0179] In an embodiment, a method performed by a radio unit (RU) is provided. The method may include an operation of receiving, from a distributed unit (DU), a control plane (C-plane) message including section information for user equipment (UE) scheduling information and section extension information for group configuration of multiple ports. The section information may include information regarding a resource region of a section description and UE identification information. The section extension information may include information regarding a beam group type, information regarding the number of one or more ports indicated by the section extension information, and port-specific UE identification information. The method may include an operation of identifying, based on the UE identification information of a designated port set to 0x7FFF in the C-plane message, that the resource region is not allocated to the designated port.

[0180] According to one embodiment, the multiple ports can share the section information within the RU. The multiple ports can include a representative port and the one or more ports indicated by the section extension information. The information about the beam group type can be "10b." The port-specific UE identification information can include UE identification information for each of the one or more ports.

[0181] According to one embodiment, the UE identity of the designated port may be included in the section information or the section extension information. The section information may correspond to section type 5. The section extension information may correspond to section extension 10. The UE identity of the designated port may be indicated by 15 bits.

[0182] According to one embodiment, the information about the resource region may include information about a starting physical resource block (PRB) of the section description and information about the number of consecutive PRBs of the section description. The UE identification information of the specified port being 0x7FFF may indicate that a layer corresponding to the specified port is not scheduled within a PRB of the section description.

[0183] According to an embodiment, the method may further include an operation of obtaining beamforming weights. The set of UE identification information included in the section information and the section extension information may be associated with UEs and UE layers to be jointly scheduled in multi-user (MU)-multiple input multiple output (MIMO) scheduling. The beamforming weights may be obtained based on at least a portion of channel information of the set of UE identification information. The beamforming weights may be obtained based on the resource region of the specified port being non-scheduled.

[0184] In an embodiment, a method performed by a distributed unit (DU) is provided. The method may include an operation of setting UE identification information of a designated port that is not to be scheduled to 0x7FFF. The method may include an operation of transmitting a control plane (C-plane) message to a radio unit (RU), the control plane (C-plane) message including section information for user equipment (UE) scheduling information and section extension information for group configuration of multiple ports. The section information may include information regarding a resource region of a section description and UE identification information. The section extension information may include information regarding a beam group type, information regarding the number of one or more ports indicated by the section extension information, and port-specific UE identification information. The UE identification information of the designated port in the C-plane message may indicate that the resource region is not allocated to the designated port.

[0185] According to one embodiment, the multiple ports can share the section information within the RU. The multiple ports can include a representative port and the one or more ports indicated by the section extension information. The information about the beam group type can be "10b." The port-specific UE identification information can include UE identification information for each of the one or more ports.

[0186] According to one embodiment, the UE identity of the designated port may be included in the section information or the section extension information. The section information may correspond to section type 5. The section extension information may correspond to section extension 10. The UE identity of the designated port may be indicated by 15 bits.

[0187] According to one embodiment, the information about the resource region may include information about a starting physical resource block (PRB) of the section description and information about the number of consecutive PRBs of the section description. The UE identification information of the specified port being 0x7FFF may indicate that a layer corresponding to the specified port is not scheduled within a PRB of the section description.

[0188] According to an embodiment, the set of UE identities included in the section information and the section extension information may be associated with UEs and UE layers that are jointly scheduled in multi-user (MU)-multiple input multiple output (MIMO) scheduling. At least some channel information of the set of UE identities may be used to calculate beamforming weights. The beamforming weights may be calculated based on non-scheduling of the resource region of the specified port.

[0189] In an embodiment, an electronic device for a radio unit (RU) is provided. The electronic device may include a memory including instructions, at least one transceiver configured to transmit or receive signals over a fronthaul interface, and at least one processor. When executed by the at least one processor, the instructions may cause the RU to receive, from a distributed unit (DU), a control plane (C-plane) message including section information for user equipment (UE) scheduling information and section extension information for group configuration of multiple ports. The section information may include information regarding a resource region of a section description and UE identification information. The section extension information may include information regarding a beam group type, information regarding the number of one or more ports indicated by the section extension information, and port-specific UE identification information. When executed by the at least one processor, the instructions may cause the RU to identify that the resource region is not allocated to a designated port based on the UE identification information of the designated port set to 0x7FFF in the C-plane message.

[0190] In an embodiment, an electronic device for a distributed unit (DU) is provided. The electronic device may include a memory including instructions, at least one transceiver configured to transmit or receive signals over a fronthaul interface, and at least one processor. The instructions, when executed by the at least one processor, may cause the DU to set UE identification information of a designated port that is not to be scheduled to 0x7FFF. The instructions, when executed by the at least one processor, may cause the DU to transmit a control plane (C-plane) message to a radio unit (RU) including section information for user equipment (UE) scheduling information and section extension information for group configuration of multiple ports. The section information includes information regarding a resource region of a section description and UE identification information, and the section extension information may include information regarding a beam group type, information regarding the number of one or more ports indicated by the section extension information, and port-specific UE identification information. The UE identification information for the designated port in the C-plane message may indicate that the resource region is not allocated to the designated port.

[0191] In an embodiment, a non-transitory computer-readable medium is provided. The non-transitory computer-readable medium may include a memory storing a program including instructions. When executed by a processor of a radio unit (RU), the instructions may cause the RU to receive, from a distributed unit (DU), a control plane (C-plane) message including section information for user equipment (UE) scheduling information and section extension information for group configuration of multiple ports, and to identify, based on UE identification information of a designated port set to 0x7FFF in the C-plane message, that a resource region in the section description is not allocated to the designated port. The section information may include information about the resource region and UE identification information. The section extension information may include information about a beam group type, information about the number of one or more ports indicated by the section extension information, and port-specific UE identification information.

[0192] In an embodiment, a non-transitory computer-readable medium is provided. The non-transitory computer-readable medium may include a memory storing a program including instructions. When executed by a processor of a distributed unit (DU), the instructions may cause the DU to set UE identification information of a designated port not to be scheduled to 0x7FFF and transmit a control plane (C-plane) message to a radio unit (RU), the control plane (C-plane) message including section information for user equipment (UE) scheduling information and section extension information for group configuration of multiple ports. The section information may include information regarding a resource region of a section description and UE identification information. The section extension information may include information regarding a beam group type, information regarding the number of one or more ports indicated by the section extension information, and port-specific UE identification information. The UE identification information of the designated port in the C-plane message may indicate that the resource region is not allocated to the designated port.

[0193] An electronic device and method according to embodiments of the present disclosure can improve beamforming performance in an RU by indicating unscheduled layers over the fronthaul interface.

[0194] The effects obtained by the present disclosure are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the following description.

[0195] The methods according to the embodiments claimed or described in the specification of the present disclosure can be implemented in hardware, software, or a combination of hardware and software.

[0196] When implemented in software, a computer-readable storage medium may be provided that stores one or more programs (software modules). The one or more programs stored on the computer-readable storage medium are configured for execution by one or more processors in an electronic device. The one or more programs include instructions that cause the electronic device to perform a method according to an embodiment described in the claims or specification of the present disclosure.

[0197] Such programs (software modules, software) can be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage device, compact disc-ROM (CD-ROM), digital versatile disc (DVD) or other form of optical storage device, magnetic cassette, or in memory consisting of some or all of these. Also, each component memory may be included in plural.

[0198] The program may also be stored in an attachable storage device accessible via a communication network such as the Internet, an intranet, a local area network (LAN), a wide area network (WAN), or a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device that executes an embodiment of the present disclosure via an external port. Furthermore, a separate storage device on the communication network may be connected to a device that executes an embodiment of the present disclosure.

[0199] In the specific embodiments of the present disclosure described above, elements included in the disclosure are expressed in the singular or plural form according to the specific embodiments presented. However, the expressions in the singular or plural form are selected to suit the presented circumstances for the convenience of explanation, and the present disclosure is not limited to the singular or plural elements, and elements expressed in the plural form may be composed of the singular or the plural.

[0200] In the detailed description of the present disclosure, specific embodiments have been described, but it goes without saying that various modifications are possible without departing from the scope of the present disclosure.

Claims

1. 1. A method performed by a radio unit (RU), comprising: receiving, from a distributed unit (DU), a control plane (C-plane) message including section information for UE (user equipment) scheduling information and section extension information for group configuration of multiple ports, the section information including information on a resource region of a section description and a UE identifier, and the section extension information including information on a beam group type, information on the number of one or more ports indicated by the section extension information, and a port-specific UE identifier; If a UE identifier for a designated port is set to 0x7FFF in the C-plane message, the method includes an act of identifying that the resource region is not allocated to the designated port.

2. The plurality of ports share the section information within the RU; the plurality of ports includes a representative port and the one or more ports indicated by the section extension information; The information about the beam group type is “10b”, The method of claim 1 , wherein the port-specific UE identifier includes a UE identifier for each port of the one or more ports indicated by the section extension information.

3. The UE identifier of the specified port is included in the section information or the section extension information; The section information corresponds to section type 5, the section extension information corresponds to section extension 10; The method of claim 1 , wherein the UE identifier of the designated port is indicated by 15 bits.

4. The information about the resource region includes information about a starting PRB (physical resource block) of the section description and information about the number of consecutive PRBs of the section description; The method of claim 1 , wherein the UE identifier of the designated port being 0x7FFF indicates that a layer corresponding to the designated port is not scheduled within a PRB of the section description.

5. further comprising the act of obtaining beamforming weights; A set of UE identifiers included in the section information and the section extension information is associated with UEs and layers of UEs that are jointly scheduled in multi-user (MU)-multiple input multiple output (MIMO) scheduling; the beamforming weights are obtained based on channel information of at least a portion of the set of UE identities; The method of claim 1 , wherein the beamforming weights are obtained based on non-scheduling of the resource region of the specified port.

6. A method performed by a distributed unit (DU), comprising: setting the UE identifier of the designated non-scheduled port to 0x7FFF; and transmitting a control plane (C-plane) message to a radio unit (RU), the control plane (C-plane) message including section information for user equipment (UE) scheduling information and section extension information for group configuration of multiple ports; The section information includes information about a resource region of a section description and a UE identifier, and the section extension information includes information about a beam group type, information about the number of one or more ports indicated by the section extension information, and a port-specific UE identifier; The UE identifier of the designated port in the C-plane message indicates that the resource region is not allocated to the designated port.

7. The plurality of ports share the section information within the RU; the plurality of ports includes a representative port and the one or more ports indicated by the section extension information; The information about the beam group type is “10b”, the port-specific UE identifier includes a UE identifier for each of the one or more ports; The UE identifier of the designated port is included in the section information or the section extension information; The section information corresponds to section type 5, the section extension information corresponds to section extension 10; The method of claim 6 , wherein the UE identifier of the designated port is indicated by 15 bits.

8. The information about the resource region includes information about a starting PRB (physical resource block) of the section description and information about the number of consecutive PRBs of the section description; The method of claim 6 , wherein the UE identifier of the designated port being 0x7FFF indicates that a layer corresponding to the designated port is not scheduled within a PRB of the section description.

9. A set of UE identifiers included in the section information and the section extension information is associated with UEs and layers of UEs that are jointly scheduled in multi-user (MU)-multiple input multiple output (MIMO) scheduling; channel information of at least a portion of the set of UE identifiers is used to calculate beamforming weights; The method of claim 6 , wherein the beamforming weights are calculated based on non-scheduling of the resource region of the designated port.

10. An RU (radio unit), a memory containing instructions; at least one transceiver configured to transmit or receive signals over the fronthaul interface; at least one processor; The instructions, when executed by the at least one processor, cause the RU to: Receive a control plane (C-plane) message from a distributed unit (DU), the control plane (C-plane) message including section information for UE (user equipment) scheduling information and section extension information for group configuration of multiple ports, the section information including information on a resource region of a section description and a UE identifier, and the section extension information including information on a beam group type, information on the number of one or more ports indicated by the section extension information, and a port-specific UE identifier; If the UE identifier of the designated port in the C-plane message is set to 0x7FFF, the RU is caused to identify that the resource region is not allocated to the designated port.

11. The RU of claim 10, wherein the instructions, when executed by the at least one processor, cause the RU to perform the operations of claims 2 to 5.

12. A distributed unit (DU), a memory containing instructions; at least one transceiver configured to transmit or receive signals over the fronthaul interface; at least one processor; The instructions, when executed by the at least one processor, cause the DU to: Set the UE identifier of the designated non-scheduled port to 0x7FFF; Inducing a control plane (C-plane) message including section information for UE (user equipment) scheduling information and section extension information for group configuration of multiple ports to be transmitted to a radio unit (RU); The section information includes information about a resource region of a section description and a UE identifier, and the section extension information includes information about a beam group type, information about the number of one or more ports indicated by the section extension information, and a port-specific UE identifier; The UE identifier of the designated port in the C-plane message indicates that the resource region is not allocated to the designated port.

13. The DU of claim 12, wherein the instructions, when executed by the at least one processor, cause the DU to perform the operations of claims 6 to 9.

14. A non-transitory computer-readable medium, the non-transitory computer-readable medium including a memory that stores a program including instructions; The instructions, when executed by a processor of a radio unit (RU), cause the RU to: Receive a control plane (C-plane) message from a distributed unit (DU), the control plane (C-plane) message including section information for UE (user equipment) scheduling information and section extension information for group configuration of multiple ports, the section information including information on a resource region of a section description and a UE identifier, and the section extension information including information on a beam group type, information on the number of one or more ports indicated by the section extension information, and a port-specific UE identifier; A non-transitory computer-readable medium that causes a UE to identify that the resource region is not allocated to the designated port if the UE identifier of the designated port is set to 0x7FFF in the C-plane message.

15. A non-transitory computer-readable medium, the non-transitory computer-readable medium including a memory that stores a program including instructions; The instructions, when executed by a processor in a distributed unit (DU), cause the DU to: Set the UE identifier of the designated non-scheduled port to 0x7FFF; Inducing a control plane (C-plane) message including section information for UE (user equipment) scheduling information and section extension information for group configuration of multiple ports to be transmitted to a RU (radio unit); The section information includes information about a resource region of a section description and a UE identifier, and the section extension information includes information about a beam group type, information about the number of one or more ports indicated by the section extension information, and a port-specific UE identifier; The non-transitory computer-readable medium, wherein the UE identifier of the designated port in the C-plane message indicates that the resource region is not allocated to the designated port.

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